Eight blasts hit locations including churches and hotels across Sri Lanka, leaving at least 290 people dead and 500 injured
Congregations were taking part in Easter Sunday services at the churches when the blasts hit
The five-star Shangri-La, Kingsbury and Cinnamon Grand hotels in the heart of Colombo were targeted
A local group named as National Thowheed Jamath are believed to be behind the attack
Officials say 24 people have been arrested in connection with the attacks
More information has emerged about the number of Indian nationals killed in the attacks.
The death toll has increased from seven to eight. All of the victims were from the southern state of Karnataka, the Indian embassy in Sri Lanka says.
Image source, EPASt Anthony's Church in the capital, Colombo
St Anthony's Church, the site of one of Sunday's most deadly attacks, is more than just a place of worship, writes the BBC's Ayeshea Perera from the scene in Colombo:
For the first time in its 175-year history, people are being turned away.
Near its entrance, half hidden by a wall, you can see bits of rubble and shards of glass. The clock on its left tower is frozen at 8.45 - the time the blast took place.
Among those gathered outside the church is Prabath Buddhika. Although Mr Buddhika is Buddhist by religion, like many others, he is a strong believer in the power of St Anthony.
Mr Buddhika ran to the church after hearing the explosions. The carnage he saw there could not be described, he says, but people fearlessly came forward from around the area in order to help.
Image source, Getty ImagesInterpol - the International Criminal Police Organisation - says it is sending an Incident Response Team (IRT), external to assist with crime scene investigation, the examination of explosives, counter-terrorism and victim identification.
"If required, additional expertise in digital forensics, biometrics, as well as photo and video analysis will also be added to the team on the ground" the organisation said.
"The families and friends of the victims of these bombings, as with every terrorist attack, require and deserve the full support of the global law enforcement community," Interpol secretary general Jürgen Stock added.
Allow Twitter content?
This article contains content provided by Twitter. We ask for your permission before anything is loaded, as they may be using cookies and other technologies. You may want to read Twitter’s cookie policy, external and privacy policy, external before accepting. To view this content choose ‘accept and continue’.
US Secretary of State Mike Pompeo has said America will continue fighting "radical Islamic terror", which he said remained a threat following the attacks in Sri Lanka.
"Sadly, this evil exists in the world," he told reporters on Monday. "This is America's fight, too."
Mr Pompeo said that he had spoken to Sri Lanka's Prime Minister Ranil Wickremesinghe over the telephone.
He earlier tweeted to condemn the "brutal" attacks, adding that the US offered its "deepest condolences".
Allow Twitter content?
This article contains content provided by Twitter. We ask for your permission before anything is loaded, as they may be using cookies and other technologies. You may want to read Twitter’s cookie policy, external and privacy policy, external before accepting. To view this content choose ‘accept and continue’.
Image source, ReutersOfficials inspect the damage caused by a bomb at St Sebastian's Church in Negombo
A previously unknown group called the National Thowheed Jamath (NTJ) is being accused of having carried out the attacks - even though no group has yet admitted the carnage.
The NTJ is believed to have splintered off from another hardline Islamist group in the country, the Sri Lanka Thowheed Jamath (SLTJ).
So who are they? You can read more about the group here.
The UK's High Commissioner to Sri Lanka, James Dauris, has described the attacks as "tragic and traumatic" and said he's spoken with Britons in hospital "who have been affected by today's senseless attacks".
"We have tremendous sympathy and are sorrowful for their loss. We are extending all the support to all those who are here and back in the UK," he told the BBC.
"Our appeal is for people to get in touch with their families back home, look at our travel advisory on how to travel safely.
"We are worried about the potential consequences of yesterday’s attack on the harmony that has been built over years. It’s not impossible that other attacks might happen."
Earlier on Monday, officials confirmed that eight British citizens had been killed in the attacks.
Allow Twitter content?
This article contains content provided by Twitter. We ask for your permission before anything is loaded, as they may be using cookies and other technologies. You may want to read Twitter’s cookie policy, external and privacy policy, external before accepting. To view this content choose ‘accept and continue’.
More on the explosion today near a church in the capital, Colombo, where scores were killed during Easter services on Sunday.
The blast occurred in a van near St Anthony's Shrine. Bomb disposal experts had been trying to defuse explosives inside the vehicle, which had been used by the attackers.
A witness told Reuters news agency: "The van exploded when the bomb defusing unit of the STF (Special Task Force) and air force tried to defuse the bomb."
It is not clear if anybody was injured during the small explosion.
Image source, ReutersBomb disposal experts cordon off an area surrounding the van as they prepare to defuse a suspected explosive device
Image source, ReutersResidents with homes near the church are told to leave as bomb experts arrive in the area
Image source, ReutersPolice clear an area in the capital while bomb squad officers inspect the van
Image source, ReutersBomb disposal officers pictured at the site after the van exploded
Sri Lanka was rocked by a wave of deadly bombings on Easter Sunday that targeted churches and high-end hotels. Here's the latest:
Image source, Getty ImagesA soldier stands guard on a street in the Sri Lankan capital, Colombo
The US State Department has issued revised travel advice, external, urging greater caution for those visiting Sri Lanka.
"Terrorist groups continue plotting possible attacks in Sri Lanka," the department says, adding: "Terrorists may attack with little or no warning, targeting tourist locations... airports, and other public areas."
Other governments, including Japan and Australia, have also cautioned citizens planning travel to Sri Lanka.
Japan's Prime Minister Shinzo Abe has joined leaders from around the world in sending his condolences to victims of the attacks.
One Japanese national was among those killed in the Easter Sunday bombings.
"I would like to offer my prayers for the victims of the attacks, external, as well as my heartfelt condolences to the families of the deceased and my sympathies to the wounded," he said in a statement.
"Such an act of terrorism cannot be justified, and Japan firmly condemns it. Japan is firmly committed to combating terrorism in co-operation with Sri Lanka and the international community."
People have gathered at a morgue in Colombo to identify loved ones who were killed in the Easter Sunday bomb attacks.
Image source, AFP
Image source, AFPNot much is known about the group Sri Lankan officials believe was behind the attacks.
However, Alan Keenan, the Sri Lanka director for the non profit organisation, International Crisis Group, suggests National Thowheed Jamath may be the same group that was involved in a "small but nonetheless important incident" last year.
"In December in the town of Marwanella... [some] statues of the Buddha were smashed and the police eventually arrested a group of young men who were said to have been the students of a preacher who's named in the intelligence document that came out yesterday," he told the BBC.
Image source, AFPFor the second day in a row, Pope Francis has condemned the attacks in Sri Lanka.
He told tens of thousands of people in St Peter's Square that he was praying for all those killed and injured in the Easter Sunday attacks.
"I ask everyone not to hesitate to offer this dear nation all the help necessary. I hope that everyone condemns these terrorist acts, inhuman acts, never justifiable," he said before leading a prayer for the victims.
Police have confirmed that a vehicle blown up earlier today was used by attackers on Sunday:
Allow Twitter content?
This article contains content provided by Twitter. We ask for your permission before anything is loaded, as they may be using cookies and other technologies. You may want to read Twitter’s cookie policy, external and privacy policy, external before accepting. To view this content choose ‘accept and continue’.
Image source, EPAPeople have been leaving flowers outside the Sri Lankan embassy in Moscow, Russia, paying tribute to those who lost their lives in the attacks.
BBC journalist Yogita Limaye is on the ground in Sri Lanka, where she visited St Sebastian church.
Dozens were killed at the church in a bomb attack on Sunday.
She tweets:
Allow Twitter content?
This article contains content provided by Twitter. We ask for your permission before anything is loaded, as they may be using cookies and other technologies. You may want to read Twitter’s cookie policy, external and privacy policy, external before accepting. To view this content choose ‘accept and continue’.
According to CNN, about 1,000 people were gathered at the church , externalwhen the bomb exploded on Sunday.
BBC Monitoring
The world through its media
Saudi Arabia's national carrier airline has said that two of its crew members are unaccounted for following a series of explosions at several churches and hotels in Sri Lanka.
In a statement on Twitter on 21 April, Saudia said two crew members were missing, while another air hostess was hospitalised in the Sri Lankan capital Colombo with "minor injuries".
The statement did not mention the nationalities of the missing and injured and did not say where they were at the time of the blasts.
Saudi newspaper Arab News reported that the two missing crew members were Saudi nationals.
UAE-based Gulf News said the crew members had been staying at the Cinnamon Grand hotel in Colombo at the time of the attacks.
At least one new explosion has been reported in Colombo.
Video footage from St Anthony's Shrine, shared by Guardian journalist Michael Safi, showed people running from the area in panic.
He said there had been a "small explosion".
The shrine was one of the places targeted by the bomb attacks on Easter Sunday.
Allow Twitter content?
This article contains content provided by Twitter. We ask for your permission before anything is loaded, as they may be using cookies and other technologies. You may want to read Twitter’s cookie policy, external and privacy policy, external before accepting. To view this content choose ‘accept and continue’.
According to BBC Sinhala's Azzam Ameen, external, the blast happened while "security forces personnel... tried to defuse a newly discovered explosives in a vehicle".
These police officers were photographed inspecting the damage at the St. Sebastian Catholic Church in Negombo on Monday:
Image source, ReutersDebris covers the floor at St Sebastian Catholic Church
Image source, ReutersThe church was badly damaged in the attacks
Imran Qureshi
BBC World Service, Bangalore, India
Five Indian political party workers lost their lives in the Colombo blasts just as they reached the Shangri La Hotel for breakfast, family members have confirmed.
The Janata Dal Secular (JDS) workers, from Bengaluru, had decided to holiday in Sri Lanka after the polling for the Lok Sabha elections in southern Karnataka ended on 18 April.
"They reached the hotel around 08:00 or so and headed straight to the breakfast table when they were killed,’’ S Shivakumar, whose brother-in-law Shivanna died in the explosion, told BBC Hindi.
Shivanna's colleagues KG Hanumantharaya, M Rangappa, K M Laxminarayan and Lakshmana Gowda Ramesh were also killed in the blast.
However, the whereabouts of the other two members of their group is unknown, according to both family members and government officials, who spoke on condition of anonymity.
Image source, ReutersThe damaged Shangri-La hotel
In another part of the same hotel, 60-year-old Indian national Razeena Khader Kukkady lost her life as she waited for her brother to pick her up.
She had seen her husband, Abdul Khader Kukkady, off to Dubai earlier that morning.
"We are all in a state of shock. Her funeral got over this morning. They could not keep the body for her children to arrive from the US because it was in a bad state,’’ her brother-in-law Usman Kukkady told BBC Hindi.