In less than a week, the Taliban have taken over the capitals of more than a quarter of Afghanistan’s provinces, advancing at an unexpectedly rapid pace.

Afghan forces say they are battling to regain control of some of the cities, and the US has been launching air strikes against the Taliban in parts of the country.

The violence has resulted in an acute humanitarian crisis, with tens of thousands displaced and barely enough aid to supply even basic resources.

UK Prime Minister Boris Johnson has defended his country's role in Afghanistan, but insisted there was no military solution to the Taliban's rapid advance.

"It is very difficult obviously, but I think the UK can be extremely proud of what has been done in Afghanistan over the last 20 years," he said, noting that the "vast bulk" of the remaining British embassy staff in Kabul would return to the UK.

"I think we've got to be realistic about the abilities of the the UK or any power to impose a military solution, a combat solution in Afghanistan," he continued.

He added that government officials were being sent to help speed up attempts to find Afghans who had worked with the British army.

Image source, Getty Images

Families arriving in the capital Kabul have spoken of the Taliban's "barbaric behaviour" in the areas that have fallen to the group, an aid worker in the capital Kabul has told the BBC.

Abdul Ghafur, the founder and director of Afghanistan Migrants Advice and Support, which is helping Afghans displaced by the fighting, told the BBC's Outside Source that the militants' public claims to have changed from their previous rule were "propaganda".

"We have families where the children have been beaten up in front of their families, we have people where their younger daughters have been forcibly married to Taliban fighters."

He added that "no one was ready for this disaster that has been unfolding in Afghanistan", or the thousands of people who have been forced to leave their homes across the country.

Around 7,000 families have arrived in Kabul alone, Abdul Ghafur said, adding that both local and international NGOs were struggling to help the new arrivals, many of whom are sleeping in mosques, the homes of local people or even on the streets.

The Taliban have made rapid territorial gains in Afghanistan the past few weeks. Having already captured rural areas and border crossings, they’ve now seized a number of provincial capitals.

The government still remains in control of some of the most important urban centres, but with international troops nearly all gone there are increasing concerns about the pace of the Taliban’s advance and what it means for those under their rule.

BBC Afghanistan correspondent Secunder Kermani was given rare access to newly captured Taliban territory in the north of the country – where militants have been encircling the city of Mazar-e-Sharif.

Image source, EPA

Nato says it will support Afghanistan's government as much as possible.

“Our aim remains to support the Afghan government and security forces as much as possible. The security personnel is paramount,” Secretary General Jens Stoltenberg said. “Nato will maintain our diplomatic presence in Kabul, and continue to adjust as necessary.”

He said that Nato - a powerful political and military alliance between 30 European and North American countries - was concerned about the high levels of violence caused by the Taliban’s offensive and reports of human rights abuses.

“The Taliban need to understand that they will not be recognised by the international community if they take the country by force. We remain committed to supporting a political solution to the conflict,” Mr Stoltenberg said.

As more of Afghanistan falls to the Taliban, one woman spoke to the BBC about her emotions.

"We have memories from each part of the city and all of this country and now (we're) looking at all of it, crumbling down right in front of our eyes and not being able to do anything about it," said Freshta Karim, an Afghan children's rights activist who runs a mobile children's library in the capital Kabul.

"So there's such a feeling of grief at the same moment too, as well as we are afraid for our lives and also worried for people because we understand that the poorest of this country suffers the most from this war."

She described the agreement between the US and the Taliban in early 2020 as "the most shameful deal of history".

The Taliban are "are against life.. against anything beautiful and alive", she said.

"Already we are seeing that they are marrying girls as young as 12 years old, they are taking revenge, they are punishing people. Why is the West trusting them?

"This is the biggest war against women in our current times and unfortunately the world is watching it silently."

You can watch the interview here:

Image source, Getty Images

As the Taliban continues to gain ground, former US President Donald Trump has lashed out at the administration of his successor, Joe Biden.

“Tragic mess in Afghanistan, a completely open and broken Border, crime at record levels, oil prices through the roof, inflation rising, and taken advantage of by the entire world - DO YOU MISS ME YET?,” he said in a short statement, published by his spokesperson on Twitter., external

In February 2020, under the Trump administration, the US signed a deal with the Taliban pledging to withdraw all American and Nato troops.

In return, as part of the agreement, the Taliban agreed not to allow al-Qaeda or any other extremist group to operate in the areas of their control.

However, the deal did not include the Afghan government, which the Taliban was then refusing to negotiate with. Peace talks have since begun, but as yet no deal has been reached.

Tens of thousands of ordinary people have had to flee their homes – with hundreds killed or injured in recent weeks – as Taliban insurgents continue to gain ground in Afghanistan.

As foreign troops withdraw, many Afghans fear a brutal return to the regime of the 1990s, which was characterised by public executions, stonings and girls being banned from school.

But what do the Taliban want from Afghanistan now?

The BBC's Yalda Hakim has been to speak to two high-profile figures in its chain of command – and heard two very different messages.

One man in London has told the BBC that he fears for his family in the western Afghan city of Herat, which is now under Taliban control.

The man, who did not give his name for safety reasons, says he has "not been able to sleep for a couple of weeks now".

He has brothers in Herat, one of whom was an advisor to the government and was imprisoned "in chains" by the Taliban in 1999.

"I really fear for him. He has been seen in the past with NGOs and Americans and is now in hiding," he said.

The man, who came to the UK in 1999 said that he spoke with his brother yesterday and urged him not to go home.

He added that the situation was calmer now but warned that things could get worse.

"The Taliban won't do anything but then they will start showing they have control."

Image source, Getty Images

Former US Secretary of State Mike Pompeo has ripped into President Joe Biden for his "panicked" tactics in Afghanistan.

"[It] looks like they have not been able to execute this," he told Fox News, external, accusing the Biden administration of poor planning and leadership.

"I don't know exactly how they're doing it, but we had conditions attached to how we were thinking about this withdrawal," said Mr Pompeo. The plan to withdraw US forces from Afghanistan was originally put forward by the administration of President Donald Trump, in which Mr Pompeo served.

"I hope that we are now in a place to get our folks out of there in a way that is rational and consistent not only with the need to get our Americans home, but making sure that this ungoverned space doesn't become another hotbed for al-Qaeda or [Islamic State] or some other radicalist Islamic terrorist group."

Terrified young men and women across Kabul have been sending the BBC’s Yalda Hakim desperate messages begging for help.

“They have grown up with freedoms and opportunities that they fully embraced,” she says. “Now they tell me they feel completely abandoned by the democratic world they thought they were part of.”

Taliban frontline commanders and foot soldiers told her that they are determined to re-impose their version of Sharia law – including stoning for adultery and preventing girls from going to school beyond the age of 12.

Read more about the fears of young Afghans as the Taliban advance to Kabul.

Image source, Getty Images

The last time the Taliban took control of Kabul was in 1996. It came after four years of civil war in Afghanistan.

Insurgents seized control of the city, with Taliban flags flown from government offices.

One of their first moves was to publicly execute former President Mohammad Najibullah.

Under the insurgents’ rule, women were banned from work and girls were not allowed to attend school. Women had to cover their face and be accompanied by a male relative outside their homes.

Punishments such as stoning to death and amputations were introduced.

Reality Check

Image source, Reuters

As Washington poured in billions of dollars to fight the Taliban insurgency and fund reconstruction after invading in 2001, troop numbers went up.

Other countries were also part of the foreign military presence, but the US had by far the biggest single contingent - and racked up the largest bill.

Between 2010 to 2012, when the US for a time had more than 100,000 soldiers in Afghanistan, the cost of the war had reached almost $100bn a year, going by official figures.

One academic study, which looked at war costs in both Afghanistan and Pakistan, estimated the US had spent around $978bn since the 2001 (this includes money allocated for 2020)

The UK and Germany - which had the largest numbers of troops after the US - spent an estimated $30bn and $19bn respectively

Read more on the costs of the war here

As we mentioned earlier, a number of countries have announced plans to evacuate their citizens.

Norway has joined them, temporarily closing its embassy in Kabul. It says it will evacuate diplomats, local employees and their families.

Finland is set to evacuate 130 of its staff, according to a minister.

Meanwhile, France has reiterated calls for its citizens to leave Afghanistan as soon as possible.

US troops have already arrived in Kabul to help evacuate American citizens, according to the BBC's partner network, CBS.

Image source, Getty Images

We've been reporting on concerns about food insecurity in Afghanistan, now the Taliban are capturing more territory.

Tomson Phiri, a spokesperson for the UN's World Food Programme (WFP), has told the BBC that currently one in three Afghans - around 14 million people - are "acutely food insecure".

"This means people have lost their means by which they earn their keep, and some two million children need nutrition treatment," said Mr Phiri.

"We fear the worst is yet to come and a larger tide of hunger is fast approaching," he added.

According to the WFP, over half of Afghanistan's population already live below the poverty line - earning less than $1.25 (90p) a day.

This food and financial instability disproportionately affect young people in Afghanistan. More than two-thirds of the country's population are under the age of 25, according to the UN.

Jon Sopel
BBC North America Editor

Image source, Getty Images

If you like neat lines, tidiness and symmetry, what's not to like about the decision of Joe Biden to pull American combat troops out of Afghanistan by 11 September 2021 - exactly 20 years on from 9/11?

In modern-day America it often feels that all roads lead back to 9/11: the single most defining - and scarring - event since Pearl Harbor in 1941, the surprise attack by the Japanese on America's Pacific fleet, which would ultimately bring America into World War Two.

Trump, if he had won last November, would have pulled out US troops, probably more quickly. Although Joe Biden inherited Trump's promise to withdraw, in policy terms the easiest thing would have been to continue to sign the cheques to pay for American servicemen and women to stay in Afghanistan for another year. And then another. And another after that.

The political pressure was by no means overwhelming - if anything, the reverse. The defence top brass, the foreign policy establishment, America's allies abroad thought anything other than the status quo would be reckless. But one question was gnawing at the new president, and it was the one posed by Hillel the Elder back in biblical times: "If not now, then when?"

Read more here.

Lead elements of the 3,000 troop deployment sent to evacuate US embassy staff have reportedly started to arrive at Karzai international airport in Kabul.

A defence official, speaking anonymously to the BBC's US partner network, CBS, said the rest are expected to arrive over the next 24 hours.

The source acknowledged the Afghan capital could be threatened by Taliban forces sooner than a recent estimate of 30 days.

The official said Taliban militants now hold power in 14 provincial capitals across the country.

Image source, EPA

Pashtana Durrani worked for a girls’ education charity in Kandahar but decided to flee the city on Thursday night as the Taliban advanced.

She told the BBC she feared for her life but she would not stop speaking out.

“I already lost my house in the morning, I already lost everything that my father left me in the morning – all his legacies, land, books, all the memories. What else do I have to lose?” she said.

She accused the Afghan government of selling out the country and its people to the Taliban.

“What were they doing? How could everything fall apart so easily?” she asked.

But she also said Western allies had failed Afghanistan by not putting its people before the Afghan government.

“Everyone involved in Afghanistan and the leadership is to blame. I don’t have any hope,” she said.

Image source, Reuters

As we mentioned earlier, Ismail Khan, a militia commander who had been leading the fight against the Taliban, has been detained.

Taliban insurgents captured him after they seized the city of Herat.

The Taliban has now shared footage of him speaking. It is not clear whether he is under duress. They ask him how he is feeling and whether he has a message for people resisting.

An official told Reuters news agency that they had promised not to harm him and other captured officials.

Rapidly unfolding events in Afghanistan are sending shockwaves throughout the international community.

Aid agencies are warning of a possible humanitarian catastrophe as civilians flee and Nato ambassadors are reportedly set to meet to discuss the deteriorating situation.

UK Prime Minister Boris Johnson will hold an emergency Cobra meeting to discuss the situation later on Friday. In an interview with the BBC, Shadow Foreign Secretary Lisa Nandy called on the government to "step up" and show it has "a clear plan" toward the situation.

Officials already announced Thursday that hundreds of troops would be deployed to help get British nationals and others safely out of the country. The Pentagon also said the US would send thousands to help evacuate its embassy staff. In other diplomatic developments:

• The diplomatic staff at the German embassy in Kabul will be reduced to the absolute minimum, with charter flights set to be brought forward
• Denmark says it will temporarily close its embassy and evacuate staff
• Sigrid Kaag, foreign minister of the Netherlands, said it would keep its embassy open as long as possible but a ministry spokesman confirmed a drawdown was under way