Attacks on Easter Sunday killed at least 253 people and were claimed by Islamic State

This article is more than 1 year old

This article is more than 1 year old

Where and when did they happen?

The attackers struck at three churches around the country and three luxury hotels in the capital, Colombo, early on Easter Sunday.

In the afternoon, as police hunted suspects, there were two more explosions near Colombo, one in a guesthouse and the other in what appears to have been the attackers’ safe house.

The deadliest attack was in the church of St Sebastian in Negombo, a satellite town just north of the capital. In the eastern town of Batticaloa, the bomber was prevented from entering the church by worshippers but killed at least 28 outside, many of them children. The third church hit was St Anthony’s Shrine in Colombo.

The three hotels hit in the first wave of attacks were the Cinnamon Grand, the Shangri-La and the Kingsbury.

The prime minister, Ranil Wickremesinghe, said a fourth hotel was also targeted, but the attack failed. He did not give further details, but sources said the man checked in to the hotel the day before the attack.

Who was killed?

Sri Lankan authorities say least 253 people were killed and many were injured, some critically. The United Nations said at least 45 of the victims were children.

On 25 April, authorities revised the death toll down from an earlier estimate of 359, giving a grim explanation for the change: the force of the explosions had done so much damage to the victims’ bodies that it had been hard to get an accurate number of dead at first, health officials said. Forensic experts were dealing with “very complex” human remains.

The vast majority of the dead were Sri Lankan, but there were also at least 38 foreigners. They included British, Indian, Danish, Dutch, Swiss, Portuguese, Spanish, American, Australian and Turkish citizens.

Who carried out the attacks?

Islamic State claimed responsibility, with several days’ delay, but the attacks appear to have been organised by a previously obscure Sri Lankan extremist group, National Thowheed Jamath.

Investigators are now trying to determine the extent of any connections between Isis and the attack cell, looking at whether Isis mostly provided violent inspiration or whether its members or former fighters helped coordinate the attacks.

At least 32 Sri Lankans are known to have joined Isis in the Middle East. Most, like the Easter attackers, came from prosperous families.

Sri Lanka’s defence minister said there were nine suicide bombers in total. Eight have been identified, though Sri Lanka has not formally named them. One was a woman.

Two of the hotels were targeted by Inshaf and Ilham Ibrahim, two brothers who were the sons of one of Sri Lanka’s wealthiest spice traders. Ilham’s wife may have been the female suicide bomber.

One of the attackers has been identified as Abdul Lathief Jameel Mohamed, who studied in London and Australia.

The leader of the attacks was named as Mohammed Zaharan, also known as Zahran Hashim, a Sri Lankan Islamist preacher who had been expelled from his community for extremist views but who reached followers through video sermons on YouTube.

Zaharan was the only figure identifiable in a video of the Sri Lanka bombers pledging loyalty to Isis, released by the group’s news agency as it claimed responsibility for the attacks.

Investigators are looking into any international connections or support the bombers may have had, including whether they travelled to neighbouring countries such as India or the Maldives for training.

Could the attacks have been prevented?

Sri Lankan authorities have come under severe criticism for what appear to have been multiple and systemic intelligence failures before the attacks.

Indian security agencies warned their Sri Lankan counterparts more than four months ago that a network of violent Islamic extremists was active in the country and likely to commit terrorist attacks, regional and western officials have told the Guardian. At least some of that information came from a suspected Isis member detained in India.

More specific warnings that extremists were planning to attack churches, even including the names of some attackers, were circulated two weeks before the attacks. Sri Lanka’s president and prime minister have both said they did not see the warnings.