Video caption: WATCH: Tear gas fired at crowd near Nika Shakarami graveWATCH: Tear gas fired at crowd near Nika Shakarami grave
Iran today saw further anti-regime protests - which have now been recorded in all 31 provinces of the country.
Earlier, security forces clamped down on crowds which had gathered to mourn the death of teenager Nika Shakarami - appearing to fire tear gas as protesters threw stones. Last month, Shakarami was found dead 10 days after she was filmed burning her headscarf at a demonstration.
Reports suggest several demonstrators have died at the hands of security forces in the past days.
Iranian President Ebrahim Raisi linked yesterday's IS-claimed attack on a Shia shrine to nationwide protests - saying the "riots" were "paving the ground for terrorist acts"
Iranian security forces attacked doctors and nurses who were protesting outside the Medical Council building in Isfahan - a day after 15 doctors were reportedly arrested at a similar protest in Tehran
Iran summoned the German ambassador in Tehran after Foreign Minister Annalena Baerbock tightened entry restrictions on Iran
Thanks for following us today. Our live page was brought to you by James FitzGerald, Laura Gozzi, Chris Giles, Imogen James, James Harness, Phelan Chatterjee, Anna Boyd, Emily McGarvey, Marita Moloney and our colleagues at BBC Persian.
A simple guide to the protests in Iran
People have been protesting across Iran for almost six weeks, defying a deadly crackdown by security forces.
The demonstrations are seen as the most serious challenge to the Iranian authorities in decades.
What are the protests about?
The unrest all started with the death of Mahsa Amini, a 22-year-old woman arrested in Tehran on 13 September for allegedly violating Iran's strict rules that require women to cover their hair with a hijab, or headscarf.
There were reports that officers beat her on the head, but the police said she suffered a heart attack.
The first protests took place after Amini's funeral in the western city of Saqqez, when women ripped off their headscarves in solidarity.
Protesters who've died in subsequent demonstrations - such as teenager Nika Shakarami - have also become figureheads of the movement.
Demos have also been held in cities around the world.
EPACopyright: EPA
Protests have spread around the world - this picture came from TurkeyImage caption: Protests have spread around the world - this picture came from Turkey
What role are women playing?
Videos have shown them defiantly setting their headscarves on fire and cutting their hair in public to chants of "woman, life, freedom" and "death to the dictator" - a reference to Supreme Leader Ayatollah Ali Khamenei.
How have authorities reacted?
They've played down the protests and tried to suppress them with force.
How many people have been killed?
The BBC and other independent media are barred from reporting from inside Iran, making it difficult to verify what is claimed by state media.
In its latest update, the Norway-based group Iran Human Rights said at least 234 people, including 29 children, have been killed by security forces.
This is evolving into a revolution, says activist
Elika Ashoori, an Iranian activist and daughter of Anoosheh Ashoori - who was detained in Iran from 2017 until earlier this year - says the protests are “slowly evolving into a revolution”.
“This is now worldwide and it’s not dying down. It’s safe to say there’s no turning back from this,” she told BBC Radio 4 earlier today, adding “something has definitely shifted in attitudes towards the Islamic republic.
“Revolutions don’t happen overnight but people have come too far to go back now - there’s been too many deaths, too many martyrs."
Ashoori, who signed a letter calling for more action against Iranian regime, says it’s “shocking to see lack of interest and cooperation from the United Nations”.
She says Iranians have violated human rights and committed so many international crimes but are "not being held accountable".
Ashoori adds: “We’ve seen countries like Germany and Canada who have made strong stances against what’s happening in Iran, but the UK has been extremely quiet."
Signs of government cutting off internet access
Netblocks, a service which tracks connectivity around the world, says there has been "major internet disruption" in the region of Mahabad.
As we reported earlier, the north-western city today saw large protests in front of government buildings. One person was reported to have been killed and another was shot dead last night.
Since the protests started last month, Iranian authorities have frequently disrupted access to the internet. Mobile internet is curtailed for a few hours in different cities on a daily basis.
The aftermath of a day of demonstrations in Tehran in 1978Image caption: The aftermath of a day of demonstrations in Tehran in 1978
Iran's 1979 revolution began with a popular democracy movement and ended with the establishment of the world's first Islamic state. The present-day authorities have been the subject of widespread protests, as we've been reporting throughout the day.
Before the revolution, Iran was ruled by Shah Mohammed Reza Pahlavi. Dissent against him grew in the 1970s, when the gap grew between the country's rich and poor.
Opposition voices rallied round Ayatollah Ruhollah Khomeini - a Shia cleric living in exile in Paris, who promised social and economic reform through a return to traditional religious values.
Protests took place towards the end of the 1970s and tensions flared between Khomeini and Pahlavi.
Getty ImagesCopyright: Getty Images
Protesters carry banners with pictures of Ruhollah Khomeini in Tehran in 1978Image caption: Protesters carry banners with pictures of Ruhollah Khomeini in Tehran in 1978
In January 1979, the Shah left Tehran and went into exile, leaving Prime Minister Shapour Bakhtiar in charge.
Bakhtiar tried to stave off the growing tide of opposition and refused to allow Khomeini to form a new government, but in February 1979, Khomeini returned from exile.
On 11 February, tanks rumbled through the streets of Tehran amid rumours of an impending military coup, but it became apparent that the army had little appetite for seizing power.
Prime Minister Bakhtiar resigned, and two months later, Khomeini won a landslide victory in a national referendum.
He declared an Islamic republic, and was appointed Iran's political and religious leader for life.
Pro-regime protesters call for 'death to England'
EPACopyright: EPA
A woman holds a sign saying "death to England" outside the British embassy in TehranImage caption: A woman holds a sign saying "death to England" outside the British embassy in Tehran
While thousands of people gathered to mark 40 days since the death of Mahsa Amini on Wednesday, a group of students gathered in front of the British embassy in Tehran as part of pro-regime demonstration.
The protesters accused the UK - where many of the TV networks and media platforms covering Iran are based - of being behind the recent unrest.
They said in a statement: "It is no longer a secret that the Persian-language media in London has become a circle of those who wish for the disintegration and humiliation of our dear Iran and have brought nothing but despair and hopelessness to the Iranian people."
Among the signs being held up by the protesters were "death to England" and "women, life, martyrdom" - instead of the "women, life, freedom" slogan used by anti-government demonstrators in recent weeks.
It comes after the Iranian government last week imposed sanctions on BBC Persian and Iran International, two Persian-language channels based in the UK, in response to earlier sanctions imposed by Western countries on Iran's morality police.
The economic issues driving some Iranians to protest
BBCCopyright: BBC
Since the protests began last month, we've been speaking to Iranians who have been taking to the streets since Mahsa Amini’s death.
Many of them spoke of how economic issues had also driven them to protest against the government. They wanted to remain anonymous and the BBC is protecting their identities.
A car salesman from Tabriz, a provincial capital in north-west Iran, said the price of medicine was a particular grievance.
He said he went to buy some amoxicillin - an antibiotic - and discovered that the price had increased more than four-fold in just days.
And on the economy more widely, he added: "Nobody comes
into my shop anymore. We used to make three or four sales every day but now,
nobody even passes before our shop."
bbcCopyright: bbc
One young man said he was angry about the rising cost of living - for example the prices of houses and cars - compared with his salary.
The issue for him and many others turning out is not the hijab, he said.
"It is the problem the Islamic Republic has with us. They all think about themselves, not thinking about us. Why so many empty promises?"
WATCH: Clash as security forces clamp down on mourners
Video content
Video caption: Iran unrest: Tear gas fired at crowd by Nika Shakarami's grave near KhorramabadIran unrest: Tear gas fired at crowd by Nika Shakarami's grave near Khorramabad
As we've been reporting, Iranian authorities launched a new crackdown on Thursday, attacking protesters who'd gathered to mourn the death of teenager Nika Shakarami.
In the clip above, you can see the clash - with protesters appearing to throw stones and security forces responding with tear gas.
How Iran is linking yesterday's IS-claimed shrine attack to protests
Yesterday, the Islamic State group claimed an attack on a Shia shrine in the city of Shiraz, which left 15 people dead and 19 wounded according to Iranian official media.
Senior Iranian officials and state-run outlets have linked this attack to protests over Mahsa Amini, 40 days after her death in police custody.
"These riots pave the ground for terrorist acts," President Ebrahim Raisi has said.
Authorities have long tried to portray the Mahsa Amini protests as "riots" masterminded by "the enemy" - a broad term which the regime has previously used to mean unfriendly countries, such as Israel or the US, or internal opponents such as Kurdish activists.
The idea is that the current unrest is being orchestrated by these "enemies" and undermining the Iranian state as a whole by creating divisions within society.
Iranian authorities have been pushing the narrative that the unrest then gives "terrorists" an opportunity to carry out such operations inside Iran.
Iran says Berlin's stance will 'provoke riots'
A look now at how all this protest action is playing out on the international stage.
Iran has summoned the German ambassador in Tehran over Berlin's stance on the demonstrations.
A day ago, German Foreign Minister Annalena Baerbock said her country would tighten entry restrictions on Iran - adding to the EU's existing package of sanctions announced after Mahsa Amini's death.
Iranian Deputy Foreign Minister Ali Baqeri Kani called Baerbock's position "unacceptable", adding that German officials' remarks would "provoke riots".
He continued: "Unfortunately, instead of fulfilling their international commitments to fight terrorism and hate speech, some European countries have turned into safe havens for terrorist groups and media outlets which are systematically producing violent content and training for disruptive and terrorist actions in Iran."
This wave of anger appears to be different
Shayan Sardarizadeh
BBC Monitoring
I've been covering
anti-regime protests in Iran for years, but I've never seen anything like
this.
For days, Iranian
authorities have been hoping that a combination of dismissal and a brutal
crackdown would bring the unrest to an end.
But this wave of anger
targeted at the regime appears to be different.
Forty days into the
demonstrations and despite a lethal response, mass arrests and an internet
shutdown, last night's protests were possibly the biggest yet.
What makes this uprising
unique is its widespread reach and depth across different sections of the
Iranian society.
Blue collar workers,
working class communities, the urban middle class, university students,
school-age teenagers and even some elderly citizens have participated.
For the first time ever,
protests have been recorded in all 31 provinces of the country, reaching
regions that had never seen rallies against the Islamic Republic before.
Any excuse or spark
brings thousands of protesters into the streets in every corner of the country.
Protesters will likely
continue to mark 40 days since the passing of many of those killed in the
unrest both locally and nationally, particularly those who, along with Mahsa
Amini and Nika Shakarami, have become the faces of this uprising.
The regime's tried and
tested tactics do not seem to be working this time.
Iranian society is more awake than ever, says protester
A woman who's been taking part in protests in Iran says she's never felt so hopeful about the future and the possibility of a change in government.
Mahsa, 27, told the BBC World Service: "You cannot imagine how tough it is to go to streets knowing that they are ready to shoot. But we are not afraid. It's not about me, it's about the next generation.
"We want to have a normal life. That's it. Nothing more.
“You should see people. Years of oppression damaged their mental health. They are angry, they are upset. They are disappointed and hopeless. I would say this is a war and we are angry.”
Mahsa goes on to say that she is optimistic about what lies ahead for Iran and how the country treats its people.
“I have never been as hopeful as I am today. I don't know when our protests will come to an end, but today Iranian society is more awake than ever and we are ready for big changes."
How did the hijab become mandatory in Iran?
Getty ImagesCopyright: Getty Images
Anti-hijab protests that erupted in Iran in 1979 carried on for daysImage caption: Anti-hijab protests that erupted in Iran in 1979 carried on for days
It might be a law now for women in Iran to wear a hijab - or headscarf - but that wasn't always the case.
The Iranian authorities' fight against "bad hijab" - wearing a headscarf or other mandatory clothing incorrectly - began soon after the 1979 Islamic Revolution, a major aim of which was to make women dress modestly.
The leader of the revolution, Ayatollah Ruhollah Khomeini, decreed that hijabs would be mandatory for all women in their workplaces and that he considered uncovered women to be "naked".
The next day, more than 100,000 people - mostly women - gathered in Tehran to protest.
It took time for authorities to decide what clothing was considered "proper". There followed in the 1980s a series of decrees on wearing modest "Islamic" clothing. As recently as August this year, President Ebrahim Raisi enforced a new list of restrictions - prompting a further pushback.
Women are now observed on surveillance cameras and can be fined if they are unveiled. If they post content against the hijab rules online, they can be sent to prison.
The so-called morality police have existed since 1979 in various forms to enforce these rules.
The above image of a young woman standing on top of a
car without wearing her hijab has gone viral, after she was photographed yesterday amid protests in Mahsa Amini’s
hometown of Saqqez in Iran.
The demonstrators were on their way to Amini’s burial site to mark 40 days since her death in police custody, which sparked the unrest.
The 40th day following an individual’s death is symbolic in Iran, and Amini’s
family were urged by authorities to hold off marking the occasion.
However, yesterday proved one of the biggest days of
demonstrations so far in the six weeks since Amini's death.
Every protester killed starts a 40-day timer
Rana Rahimpour
BBC Persian
Getty ImagesCopyright: Getty Images
There was a fresh wave of demos on Wednesday to mark 40 days since the death of Mahsa AminiImage caption: There was a fresh wave of demos on Wednesday to mark 40 days since the death of Mahsa Amini
Every time the Iranian government kills a protester, a 40-day timer is started. And if attendees of the 40th day anniversary are killed, the timer starts again.
By killing dozens of protesters, the Iranian government has entrapped itself in a vicious cycle.
The demonstrators have become energized by their unprecedented show of strength on Wednesday as they marked 40 days since the death of Mahsa Amini.
Now they are back on the streets to mark Nika Shakarami’s 40th day ceremony...
Next will be the 40th day of Sarina Esmailizadeh... and so on.
With every protest comes another brutal crackdown and with it, more deaths.
Unless the government changes its tactics - and it is showing no signs that it will - the protests will likely spiral and continue to grow.
It’s difficult to know where this movement is headed but one thing is certain. The relationship between Iranian society and the ruling establishment is broken, and few see any resolution in sight.
Medics' demonstration 'attacked' in western city
Some news now of another development from Iran today.
Doctors and nurses gathered to protest earlier in the western city of Isfahan, in front of the Medical Council building.
A source told BBC Persian that the security forces attacked the demonstration to disperse those taking part.
A similar protest happened yesterday in Tehran, which also prompted an crackdown from the security forces. At least 15 doctors were arrested, and the president of the Teheran Medical Council resigned in protest.
'Violent arrests' during latest student demonstrations
Fresh student protests have been happening across Iran today over the death of Nika Shakarami - a 16-year-old whose body was found 10 days after she was filmed burning her headscarf.
In videos published on social media, students in Tehran and elsewhere can be seen removing their own scarves and chanting anti-government slogans.
At the Pars University of Architecture and Art, students chanted: "For every single protester killed, thousands of protesters will rise."
One demonstrator from Karaj told the BBC that security forces attacked the gathering she was in and "violently arrested" at least four students.
Activists say dozens of students were arrested yesterday for participating in protests which marked 40 days since the death of another young woman, Mahsa Amini.
'I know your great soul is watching' - Shakarami's mother
BBCCopyright: BBC
Nika Shakarami's mother speaking at her daughter's gravesite in Khoram Abad todayImage caption: Nika Shakarami's mother speaking at her daughter's gravesite in Khoram Abad today
The mother of Nika Shakarami spoke earlier today in a ceremony marking the teenager's death during a wave of anti-government protests in Iran.
Speaking in Khorramabad, in Shakarami's home region, Nika's mother said: “I know your great soul is watching. In your very short life, I saw how you grew and developed.
"I saw how much you suffered and burnt."
People interrupted her speech by chanting “Khamenei is a murderer and his regime is not legitimate” - a reference to Iran's supreme leader.
Shakarami, 16, disappeared on 20 September after she was seen burning her headscarf in a protest in Tehran.
As we mentioned a short while ago, the Iranian security forces are reported to have today opened fire on demonstrators who'd gathered at a cemetery where Shakarami is buried.
Nika Shakarami, a face and symbol of the protests
Raffi Berg
BBC Online Middle East editor
BBC Persian sourceCopyright: BBC Persian source
The deaths of young protesters apparently at the hands of Iran's security forces has helped fuel the unrest which is sweeping the country.
Some have become symbols of the protests - their names and faces plastered on placards and repeated in chants.
One of the most potent is Nika Shakarami, a 16-year-old from Tehran, instantly recognisable with her two-tone bobcut hair, black T-shirt and eyeliner. Nika was found dead 10 days after she messaged a friend to say she was being chased by police.
Her case was made worse by the fact that her body was stolen by the authorities and buried secretly, according to her family. Officials say she died after falling off a building - an account her family refute.
For protesters, Nika has become an emblem and a heroine who died for their cause.
"We'll avenge you, dear Nika", read a large banner carried by a crowd of demonstrators in the western city of Borujerd on Wednesday night - one of many such scenes which have been repeated all around the country.
How Iran’s economy created conditions ripe for protests
Behrang Tajdin
Economics correspondent, BBC Persian
Mahsa Amini’s death sparked the protests we are currently seeing, but the state of Iran’s economy had already created a sense of despair.
Here are six key factors which have contributed to the country’s economic woes:
Iran’s shrunken economy: Crippling sanctions reinstated by the United States in 2018 after it abandoned a nuclear deal with Iran have hit its oil, banking and other sectors
Women out of work: The government's pursuit of higher birth rates and emphasising women's roles as stay-at-home mothers - under the orders of the supreme leader - has resulted in a significant decline in the number of women in work
Sky-rocketing prices: The cost of goods and services has increased by 1,135% over the past decade
A devalued currency: The value of Iran’s currency, the rial, has fallen by almost 90% against the US dollar on the open market exchange rate over the past five years
Falling living standards: All the above factors have combined to cause a long slump in living standards
Bleak prospects: With the prospects of the US returning to the nuclear deal and lifting its sanctions having dimmed in recent months, Iran is set to remain an isolated country, with the government relying on selling oil on the so-called grey market to make ends meet. With little hope of better, more prosperous lives in the future, many Iranians have taken aim at the whole Islamic Republic during the recent protests
Live Reporting
Edited by James FitzGerald
All times stated are UK
Get involved
Video caption: WATCH: Tear gas fired at crowd near Nika Shakarami graveWATCH: Tear gas fired at crowd near Nika Shakarami grave -
Protesters gathered in front of government buildings in the city of Mahabad, a Kurdish city in the north-west
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Iranian President Ebrahim Raisi linked yesterday's IS-claimed attack on a Shia shrine to nationwide protests - saying the "riots" were "paving the ground for terrorist acts"
-
Students continued marching at universities across the countrya day after marking 40 days since Mahsa Amini's death
-
Iranian security forces attacked doctors and nurses who were protesting outside the Medical Council building in Isfahan - a day after 15 doctors were reportedly arrested at a similar protest in Tehran
-
Iran summoned the German ambassador in Tehran after Foreign Minister Annalena Baerbock tightened entry restrictions on Iran
EPACopyright: EPA Protests have spread around the world - this picture came from TurkeyImage caption: Protests have spread around the world - this picture came from Turkey View more on twitterView more on twitter 
Getty ImagesCopyright: Getty Images The aftermath of a day of demonstrations in Tehran in 1978Image caption: The aftermath of a day of demonstrations in Tehran in 1978 
Getty ImagesCopyright: Getty Images Protesters carry banners with pictures of Ruhollah Khomeini in Tehran in 1978Image caption: Protesters carry banners with pictures of Ruhollah Khomeini in Tehran in 1978 
EPACopyright: EPA A woman holds a sign saying "death to England" outside the British embassy in TehranImage caption: A woman holds a sign saying "death to England" outside the British embassy in Tehran 
BBCCopyright: BBC 
bbcCopyright: bbc Video caption: Iran unrest: Tear gas fired at crowd by Nika Shakarami's grave near KhorramabadIran unrest: Tear gas fired at crowd by Nika Shakarami's grave near Khorramabad 
Getty ImagesCopyright: Getty Images Anti-hijab protests that erupted in Iran in 1979 carried on for daysImage caption: Anti-hijab protests that erupted in Iran in 1979 carried on for days 
TwitterCopyright: Twitter 
Getty ImagesCopyright: Getty Images There was a fresh wave of demos on Wednesday to mark 40 days since the death of Mahsa AminiImage caption: There was a fresh wave of demos on Wednesday to mark 40 days since the death of Mahsa Amini 
BBCCopyright: BBC Nika Shakarami's mother speaking at her daughter's gravesite in Khoram Abad todayImage caption: Nika Shakarami's mother speaking at her daughter's gravesite in Khoram Abad today 
BBC Persian sourceCopyright: BBC Persian source 
- Iran’s shrunken economy: Crippling sanctions reinstated by the United States in 2018 after it abandoned a nuclear deal with Iran have hit its oil, banking and other sectors
- Women out of work: The government's pursuit of higher birth rates and emphasising women's roles as stay-at-home mothers - under the orders of the supreme leader - has resulted in a significant decline in the number of women in work
- Sky-rocketing prices: The cost of goods and services has increased by 1,135% over the past decade
- A devalued currency: The value of Iran’s currency, the rial, has fallen by almost 90% against the US dollar on the open market exchange rate over the past five years
- Falling living standards: All the above factors have combined to cause a long slump in living standards
- Bleak prospects: With the prospects of the US returning to the nuclear deal and lifting its sanctions having dimmed in recent months, Iran is set to remain an isolated country, with the government relying on selling oil on the so-called grey market to make ends meet. With little hope of better, more prosperous lives in the future, many Iranians have taken aim at the whole Islamic Republic during the recent protests
Latest PostWhat's happened today?
Video content
Iran today saw further anti-regime protests - which have now been recorded in all 31 provinces of the country.
Earlier, security forces clamped down on crowds which had gathered to mourn the death of teenager Nika Shakarami - appearing to fire tear gas as protesters threw stones. Last month, Shakarami was found dead 10 days after she was filmed burning her headscarf at a demonstration.
Reports suggest several demonstrators have died at the hands of security forces in the past days.
Here's what else we have been covering:
Thanks for following us today. Our live page was brought to you by James FitzGerald, Laura Gozzi, Chris Giles, Imogen James, James Harness, Phelan Chatterjee, Anna Boyd, Emily McGarvey, Marita Moloney and our colleagues at BBC Persian.
A simple guide to the protests in Iran
People have been protesting across Iran for almost six weeks, defying a deadly crackdown by security forces.
The demonstrations are seen as the most serious challenge to the Iranian authorities in decades.
What are the protests about?
The unrest all started with the death of Mahsa Amini, a 22-year-old woman arrested in Tehran on 13 September for allegedly violating Iran's strict rules that require women to cover their hair with a hijab, or headscarf.
There were reports that officers beat her on the head, but the police said she suffered a heart attack.
The first protests took place after Amini's funeral in the western city of Saqqez, when women ripped off their headscarves in solidarity.
Protesters who've died in subsequent demonstrations - such as teenager Nika Shakarami - have also become figureheads of the movement.
Demos have also been held in cities around the world.
What role are women playing?
Videos have shown them defiantly setting their headscarves on fire and cutting their hair in public to chants of "woman, life, freedom" and "death to the dictator" - a reference to Supreme Leader Ayatollah Ali Khamenei.
How have authorities reacted?
They've played down the protests and tried to suppress them with force.
How many people have been killed?
The BBC and other independent media are barred from reporting from inside Iran, making it difficult to verify what is claimed by state media.
In its latest update, the Norway-based group Iran Human Rights said at least 234 people, including 29 children, have been killed by security forces.
This is evolving into a revolution, says activist
Elika Ashoori, an Iranian activist and daughter of Anoosheh Ashoori - who was detained in Iran from 2017 until earlier this year - says the protests are “slowly evolving into a revolution”.
“This is now worldwide and it’s not dying down. It’s safe to say there’s no turning back from this,” she told BBC Radio 4 earlier today, adding “something has definitely shifted in attitudes towards the Islamic republic.
“Revolutions don’t happen overnight but people have come too far to go back now - there’s been too many deaths, too many martyrs."
Ashoori, who signed a letter calling for more action against Iranian regime, says it’s “shocking to see lack of interest and cooperation from the United Nations”.
She says Iranians have violated human rights and committed so many international crimes but are "not being held accountable".
Ashoori adds: “We’ve seen countries like Germany and Canada who have made strong stances against what’s happening in Iran, but the UK has been extremely quiet."
Signs of government cutting off internet access
Netblocks, a service which tracks connectivity around the world, says there has been "major internet disruption" in the region of Mahabad.
As we reported earlier, the north-western city today saw large protests in front of government buildings. One person was reported to have been killed and another was shot dead last night.
Since the protests started last month, Iranian authorities have frequently disrupted access to the internet. Mobile internet is curtailed for a few hours in different cities on a daily basis.
What was the Islamic Revolution of 1979?
Iran's 1979 revolution began with a popular democracy movement and ended with the establishment of the world's first Islamic state. The present-day authorities have been the subject of widespread protests, as we've been reporting throughout the day.
Before the revolution, Iran was ruled by Shah Mohammed Reza Pahlavi. Dissent against him grew in the 1970s, when the gap grew between the country's rich and poor.
Opposition voices rallied round Ayatollah Ruhollah Khomeini - a Shia cleric living in exile in Paris, who promised social and economic reform through a return to traditional religious values.
Protests took place towards the end of the 1970s and tensions flared between Khomeini and Pahlavi.
In January 1979, the Shah left Tehran and went into exile, leaving Prime Minister Shapour Bakhtiar in charge.
Bakhtiar tried to stave off the growing tide of opposition and refused to allow Khomeini to form a new government, but in February 1979, Khomeini returned from exile.
On 11 February, tanks rumbled through the streets of Tehran amid rumours of an impending military coup, but it became apparent that the army had little appetite for seizing power.
Prime Minister Bakhtiar resigned, and two months later, Khomeini won a landslide victory in a national referendum.
He declared an Islamic republic, and was appointed Iran's political and religious leader for life.
Pro-regime protesters call for 'death to England'
While thousands of people gathered to mark 40 days since the death of Mahsa Amini on Wednesday, a group of students gathered in front of the British embassy in Tehran as part of pro-regime demonstration.
The protesters accused the UK - where many of the TV networks and media platforms covering Iran are based - of being behind the recent unrest.
They said in a statement: "It is no longer a secret that the Persian-language media in London has become a circle of those who wish for the disintegration and humiliation of our dear Iran and have brought nothing but despair and hopelessness to the Iranian people."
Among the signs being held up by the protesters were "death to England" and "women, life, martyrdom" - instead of the "women, life, freedom" slogan used by anti-government demonstrators in recent weeks.
It comes after the Iranian government last week imposed sanctions on BBC Persian and Iran International, two Persian-language channels based in the UK, in response to earlier sanctions imposed by Western countries on Iran's morality police.
The economic issues driving some Iranians to protest
Since the protests began last month, we've been speaking to Iranians who have been taking to the streets since Mahsa Amini’s death.
Many of them spoke of how economic issues had also driven them to protest against the government. They wanted to remain anonymous and the BBC is protecting their identities.
A car salesman from Tabriz, a provincial capital in north-west Iran, said the price of medicine was a particular grievance.
He said he went to buy some amoxicillin - an antibiotic - and discovered that the price had increased more than four-fold in just days.
And on the economy more widely, he added: "Nobody comes into my shop anymore. We used to make three or four sales every day but now, nobody even passes before our shop."
One young man said he was angry about the rising cost of living - for example the prices of houses and cars - compared with his salary.
The issue for him and many others turning out is not the hijab, he said.
"It is the problem the Islamic Republic has with us. They all think about themselves, not thinking about us. Why so many empty promises?"
WATCH: Clash as security forces clamp down on mourners
Video content
As we've been reporting, Iranian authorities launched a new crackdown on Thursday, attacking protesters who'd gathered to mourn the death of teenager Nika Shakarami.
In the clip above, you can see the clash - with protesters appearing to throw stones and security forces responding with tear gas.
How Iran is linking yesterday's IS-claimed shrine attack to protests
Yesterday, the Islamic State group claimed an attack on a Shia shrine in the city of Shiraz, which left 15 people dead and 19 wounded according to Iranian official media.
Senior Iranian officials and state-run outlets have linked this attack to protests over Mahsa Amini, 40 days after her death in police custody.
"These riots pave the ground for terrorist acts," President Ebrahim Raisi has said.
Authorities have long tried to portray the Mahsa Amini protests as "riots" masterminded by "the enemy" - a broad term which the regime has previously used to mean unfriendly countries, such as Israel or the US, or internal opponents such as Kurdish activists.
The idea is that the current unrest is being orchestrated by these "enemies" and undermining the Iranian state as a whole by creating divisions within society.
Iranian authorities have been pushing the narrative that the unrest then gives "terrorists" an opportunity to carry out such operations inside Iran.
Iran says Berlin's stance will 'provoke riots'
A look now at how all this protest action is playing out on the international stage.
Iran has summoned the German ambassador in Tehran over Berlin's stance on the demonstrations.
A day ago, German Foreign Minister Annalena Baerbock said her country would tighten entry restrictions on Iran - adding to the EU's existing package of sanctions announced after Mahsa Amini's death.
Iranian Deputy Foreign Minister Ali Baqeri Kani called Baerbock's position "unacceptable", adding that German officials' remarks would "provoke riots".
He continued: "Unfortunately, instead of fulfilling their international commitments to fight terrorism and hate speech, some European countries have turned into safe havens for terrorist groups and media outlets which are systematically producing violent content and training for disruptive and terrorist actions in Iran."
This wave of anger appears to be different
Shayan Sardarizadeh
BBC Monitoring
I've been covering anti-regime protests in Iran for years, but I've never seen anything like this.
For days, Iranian authorities have been hoping that a combination of dismissal and a brutal crackdown would bring the unrest to an end.
But this wave of anger targeted at the regime appears to be different.
Forty days into the demonstrations and despite a lethal response, mass arrests and an internet shutdown, last night's protests were possibly the biggest yet.
What makes this uprising unique is its widespread reach and depth across different sections of the Iranian society.
Blue collar workers, working class communities, the urban middle class, university students, school-age teenagers and even some elderly citizens have participated.
For the first time ever, protests have been recorded in all 31 provinces of the country, reaching regions that had never seen rallies against the Islamic Republic before.
Any excuse or spark brings thousands of protesters into the streets in every corner of the country.
Protesters will likely continue to mark 40 days since the passing of many of those killed in the unrest both locally and nationally, particularly those who, along with Mahsa Amini and Nika Shakarami, have become the faces of this uprising.
The regime's tried and tested tactics do not seem to be working this time.
Iranian society is more awake than ever, says protester
A woman who's been taking part in protests in Iran says she's never felt so hopeful about the future and the possibility of a change in government.
Mahsa, 27, told the BBC World Service: "You cannot imagine how tough it is to go to streets knowing that they are ready to shoot. But we are not afraid. It's not about me, it's about the next generation.
"We want to have a normal life. That's it. Nothing more.
“You should see people. Years of oppression damaged their mental health. They are angry, they are upset. They are disappointed and hopeless. I would say this is a war and we are angry.”
Mahsa goes on to say that she is optimistic about what lies ahead for Iran and how the country treats its people.
“I have never been as hopeful as I am today. I don't know when our protests will come to an end, but today Iranian society is more awake than ever and we are ready for big changes."
How did the hijab become mandatory in Iran?
It might be a law now for women in Iran to wear a hijab - or headscarf - but that wasn't always the case.
The Iranian authorities' fight against "bad hijab" - wearing a headscarf or other mandatory clothing incorrectly - began soon after the 1979 Islamic Revolution, a major aim of which was to make women dress modestly.
The leader of the revolution, Ayatollah Ruhollah Khomeini, decreed that hijabs would be mandatory for all women in their workplaces and that he considered uncovered women to be "naked".
The next day, more than 100,000 people - mostly women - gathered in Tehran to protest.
It took time for authorities to decide what clothing was considered "proper". There followed in the 1980s a series of decrees on wearing modest "Islamic" clothing. As recently as August this year, President Ebrahim Raisi enforced a new list of restrictions - prompting a further pushback.
Women are now observed on surveillance cameras and can be fined if they are unveiled. If they post content against the hijab rules online, they can be sent to prison.
The so-called morality police have existed since 1979 in various forms to enforce these rules.
Read more here.
Saqqez protester goes viral
The above image of a young woman standing on top of a car without wearing her hijab has gone viral, after she was photographed yesterday amid protests in Mahsa Amini’s hometown of Saqqez in Iran.
The demonstrators were on their way to Amini’s burial site to mark 40 days since her death in police custody, which sparked the unrest.
The 40th day following an individual’s death is symbolic in Iran, and Amini’s family were urged by authorities to hold off marking the occasion.
However, yesterday proved one of the biggest days of demonstrations so far in the six weeks since Amini's death.
Every protester killed starts a 40-day timer
Rana Rahimpour
BBC Persian
Every time the Iranian government kills a protester, a 40-day timer is started. And if attendees of the 40th day anniversary are killed, the timer starts again.
By killing dozens of protesters, the Iranian government has entrapped itself in a vicious cycle.
The demonstrators have become energized by their unprecedented show of strength on Wednesday as they marked 40 days since the death of Mahsa Amini.
Now they are back on the streets to mark Nika Shakarami’s 40th day ceremony...
Next will be the 40th day of Sarina Esmailizadeh... and so on.
With every protest comes another brutal crackdown and with it, more deaths.
Unless the government changes its tactics - and it is showing no signs that it will - the protests will likely spiral and continue to grow.
It’s difficult to know where this movement is headed but one thing is certain. The relationship between Iranian society and the ruling establishment is broken, and few see any resolution in sight.
Medics' demonstration 'attacked' in western city
Some news now of another development from Iran today.
Doctors and nurses gathered to protest earlier in the western city of Isfahan, in front of the Medical Council building.
A source told BBC Persian that the security forces attacked the demonstration to disperse those taking part.
A similar protest happened yesterday in Tehran, which also prompted an crackdown from the security forces. At least 15 doctors were arrested, and the president of the Teheran Medical Council resigned in protest.
'Violent arrests' during latest student demonstrations
Fresh student protests have been happening across Iran today over the death of Nika Shakarami - a 16-year-old whose body was found 10 days after she was filmed burning her headscarf.
In videos published on social media, students in Tehran and elsewhere can be seen removing their own scarves and chanting anti-government slogans.
At the Pars University of Architecture and Art, students chanted: "For every single protester killed, thousands of protesters will rise."
One demonstrator from Karaj told the BBC that security forces attacked the gathering she was in and "violently arrested" at least four students.
Activists say dozens of students were arrested yesterday for participating in protests which marked 40 days since the death of another young woman, Mahsa Amini.
'I know your great soul is watching' - Shakarami's mother
The mother of Nika Shakarami spoke earlier today in a ceremony marking the teenager's death during a wave of anti-government protests in Iran.
Speaking in Khorramabad, in Shakarami's home region, Nika's mother said: “I know your great soul is watching. In your very short life, I saw how you grew and developed.
"I saw how much you suffered and burnt."
People interrupted her speech by chanting “Khamenei is a murderer and his regime is not legitimate” - a reference to Iran's supreme leader.
Shakarami, 16, disappeared on 20 September after she was seen burning her headscarf in a protest in Tehran.
As we mentioned a short while ago, the Iranian security forces are reported to have today opened fire on demonstrators who'd gathered at a cemetery where Shakarami is buried.
Nika Shakarami, a face and symbol of the protests
Raffi Berg
BBC Online Middle East editor
The deaths of young protesters apparently at the hands of Iran's security forces has helped fuel the unrest which is sweeping the country.
Some have become symbols of the protests - their names and faces plastered on placards and repeated in chants.
One of the most potent is Nika Shakarami, a 16-year-old from Tehran, instantly recognisable with her two-tone bobcut hair, black T-shirt and eyeliner. Nika was found dead 10 days after she messaged a friend to say she was being chased by police.
Her case was made worse by the fact that her body was stolen by the authorities and buried secretly, according to her family. Officials say she died after falling off a building - an account her family refute.
For protesters, Nika has become an emblem and a heroine who died for their cause.
"We'll avenge you, dear Nika", read a large banner carried by a crowd of demonstrators in the western city of Borujerd on Wednesday night - one of many such scenes which have been repeated all around the country.
How Iran’s economy created conditions ripe for protests
Behrang Tajdin
Economics correspondent, BBC Persian
Mahsa Amini’s death sparked the protests we are currently seeing, but the state of Iran’s economy had already created a sense of despair.
Here are six key factors which have contributed to the country’s economic woes:
Read the full story here.