ISIS has released this picture which it claims shows seven suicide bombers alongside the mastermind who co-ordinated the Easter Sunday atrocity in Sri Lanka.

The image was released by the Amaq news agency - Daesh’s official mouthpiece - and is said to show extremist cleric Zahran Hashim, who has been identified as the man who planned the attacks, reports the mirror.co.uk.

Seven fantatics have their faces covered, but the terror group earlier named the bombers as Abu Ubayda, Abu al-Mukhtar, Abu Khalil, Abu al-Bara’a, Abu Muhammad and Abu Abdullah.

The men in the picture are all seen standing in front of an ISIS flag.

The blasts killed 321 people, including eight Britons.

In an earlier statement, the extremist organisation said: ‘The perpetrators of the attack that targeted nationals of the countries of the coalitions and Christians in Sri Lanka before yesterday are fighters from the Islamic State.’

Sri Lankan officials have blamed two local Islamic extremist group for the attack - with suspected links to foreign militants.

The government has said at least seven suicide bombers were involved.

US intelligence sources had earlier told Reuters the Sri Lanka attacks carried some of the hallmarks of Islamic State.

Sri Lankan police have arrested 40 people as part of the investigation into the bombings of three churches and three hotels, and one was a Syrian national, a source told Reuters.

The terror group claims ‘the executors of the attack that targeted citizens of coalition states & Christians in Sri Lanka two days ago were with ISIS’.

There were six explosions on the morning of Easter Sunday, three at churches and three at luxury hotels.

A planned fourth bombing, near the airport, failed.

The death cult has repeatedly called for assaults on churches, particularly since the New Zealand mosque attacks.

It did not provide any evidence to support its claim, which is being investigated by Sri Lankan authorities.

Citing the US-led military campaign against ISIS in the Middle East, the claim stated: ‘The attackers who targeted citizens of the coalition state members and Christians in Sri Lanka the day before yesterday were fighters of the Islamic State.’

Some of the bombers had travelled abroad and returned home to Sri Lanka, Prime Minister Ranil Wickremesinghe told reporters, adding that he believes there may be ‘some links’ between the attacks and ISIS.

He said it was ‘possible’ that the bombings were revenge for the New Zealand terror shootings, and that Sri Lankans who returned after joining ISIS in Syria are being monitored.

Both ISIS and al-Qaeda had called on revenge attacks after the Christchurch mosque attacks.

Sri Lanka’s prime minister says more attacks are possible, as the government blames two domestic Islamist extremist groups suspected of receiving help from foreign militants.

The early findings of the investigation have found that the attacks were committed in revenge for the mosque shootings in Christchurch, New Zealand, a month ago, a junior minister told parliament.

The FBI is assisting Sri Lankan authorities with their investigation of the bomb attacks over the Easter weekend on three churches and four hotels, a spokeswoman for the US law enforcement agency said on Tuesday.

The Washington Post earlier had reported that the FBI had offered expertise to test evidence and that analysts were scouring databases for information regarding the attacks.

Sri Lanka’s prime minister warned there were more explosives and militants ‘out there’ after the Easter suicide bombings.

Ranil Wickremesinghe made the comment at a news conference, and said some officials are likely to lose their jobs over intelligence lapses surrounding the attack.

Mr Wickremesinghe acknowledged there was a prior warning, and said India’s embassy was eyed as a possible target.

He told reporters that the government’s security agencies were monitoring Sri Lankans who had joined Islamic State and returned home.

‘We will be following up on IS claims, we believe there may be links,’ he said.

Indian intelligence officers contacted their Sri Lankan counterparts two hours before the first attack to warn of a specific threat on churches, one Sri Lankan defence source and an Indian government source told Reuters.

Another Sri Lankan defence source said a warning came ‘hours before’ the first strike.

One of the Sri Lankan sources said a warning was also sent by the Indians on Saturday night.

The Indian government source said similar messages had been given to Sri Lankan intelligence agents on April 4 and April 20.

Sri Lanka’s presidency and the Indian foreign ministry both did not respond to requests for comment.