As the Islamic State claimed responsibility for the devastating Sri Lankan bomb attacks, the country's president said his defence chiefs would be sacked for failing to act on - or even pass on - warnings of the imminent attacks.

President Maithripala Sirisena said he expected to change the heads of the country's defence forces within a day following their failure to prevent suicide bombs that killed more than 300 people, despite the fact they had prior information about the attacks.

"I will completely restructure the police and security forces in the coming weeks. I expect to change the heads of defence establishments within next 24 hours," Sirisena said in a TV address to the nation.

"The security officials who got the intelligence report from a foreign nation did not share it with me. Appropriate actions would have been taken. I have decided to take stern action against these officials."


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• IS claimed Sri Lanka church attacks, but there are many unanswered questions

Islamic State claimed responsibility on Tuesday for the bomb attacks in Sri Lanka that killed 321 people in what officials believe was retaliation for assaults on mosques in New Zealand.

The claim, issued through the group's AMAQ news agency, was made after Sri Lanka said two domestic Islamist groups with suspected links to foreign militants were suspected to have been behind the attacks at three churches and four hotels. About 500 people were also wounded in the bombings.

Prime Minister Ranil Wickremesinghe told a news conference investigators were making progress in identifying the perpetrators.

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

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

In a statement, Islamic State named what it said were the seven attackers who carried out the attacks. It gave no further evidence to support its claim of responsibility.

The hardline militant group, who have lost the territory they once held in Syria and Iraq to Western-backed forces, later released a video on Amaq showing eight assailants, seven of whom were masked, pledging allegiance to Islamic State leader Abu Bakr al-Baghdadi.


Earlier, a Sri Lanka government minister says the Easter Sunday bombings which killed more than 300 people were retaliation for the Christchurch mosque attacks.

State Minister of Defence Ruwan Wijewardene told Sri Lankan Parliament initial investigations showed the co-ordinated attacks were "carried out in retaliation for the attack against Muslims in Christchurch".

Wijewardene said two domestic Islamic organisations were responsible for the bombings, including National Thawheed Jama'ut (NTJ).

Meanwhile, Prime Minister Jacinda Ardern's office reportedly said they have "not yet seen any intelligence upon which such an assessment might be based".

Islamic State claimed responsibility for the Easter Sunday church and hotel bombings in a message shared on its al-Amaq news agency late on Tuesday, according to multiple reports.

Sri Lanka 'bombing mastermind' named

Sri Lankan intelligence has named the mastermind behind the Easter Sunday attacks as Moulvi Zahran Hashim, an extremist local cleric who incited his followers to violence with fiery sermons on his social media channels.


The revelation comes after senior government officials accused the NTJ, a little-known group promoting Islamist terrorist ideology, as the perpetrators of the horrific suicide bombings which have now killed 310 people, including eight British citizens.

India's CNN News 18 channel first reported the possible involvement of Hashim in the massacre, claiming Indian intelligence sources had indicated to the Sri Lankans that he was planning to attack the Indian High Commission in Colombo in early April.

Moulavi Zahran Hashim, a radical islamist imam and preacher, is thought to be on the run.

Over the past two years, Hashim gained thousands of followers and attracted the attention of jihad experts for his incendiary preaching on a pro-Islamic State Sri Lankan Facebook account, known as "Al-Ghuraba" media, and on YouTube.

Robert Postings, a writer and researcher on Islamic State (Isis), said on his Twitter account he had first encountered Hashim in late 2017 when the "self-styled" preacher was disseminating pro-Isis propaganda on Facebook.

YouTube videos of the Islamist who is now the face of one of the worst terrorist atrocities since 9/11 shows him railing against all non-believers, including Christians, Hindus and Buddhists, and declaring only Muslims are fit to rule. The backdrop to his sermons included images of the burning Twin Towers in New York in 2001.

Relatives bury three members of the same family who died at Easter Sunday bomb blast at St Sebastian Church. Photo / AP

There have also been conflicting reports about the fate of Hashim, with claims circulating that he was one of the suicide bombers who carried out the attack and counter-claims that he may be on the run in the neighbouring Maldives islands.


Although known primarily as a luxury honeymoon destination, the Maldives also supplied hundreds of radicalised fighters to Isis' failed attempts to set up an Islamic caliphate in the Middle East.

Hashim himself was known among the Muslim community as a divisive figure who was said to have dropped out of his seminary in India either because of ideological differences or over money worries. He is believed to have clashed with fellow clerics and encouraged his followers to attack rival mosques.

Hilmy Ahamed, the vice-president of the Muslim Council of Sri Lanka, told the Telegraph he had been trying to warn officials about Hashim's extremism for three years after it emerged that he was radicalising young pupils in his Koran classes.

"We were very concerned that this guy was preaching hate on social media and uploading a lot of videos," Ahamed said.

He said Hashim continued to shuttle between India and Sri Lanka, travelling by fishing boat to avoid detection.

Hashim's group began as an offshoot of the Sri Lanka Thawheed Jama'ut, which has repeatedly fractured due to internal disputes.


Footwear and personal belongings of victims near the scene of a suicide bombing at St Sebastian Church in Negombo. Photo / AP

The group could not have carried out the attack without external help, added Ahamed.

One working theory among regional security experts is that returning fighters could have provided training and logistics to the marginal NTJ which, although a cheerleader of global jihad, had only been known previously for defacing Buddhist statues in Sri Lanka.

In January, police in Puttalam, about 160km north of Colombo, raided a coconut plantation, where they discovered 100kg of C4 explosives, 100 detonators, 75kg of ammonium nitrate and potassium chlorate and six 20-litre cans of nitric acid.

Reports at the time did not name the group involved but said the site may be linked to a newly emerging militant group that was tied to the vandalising of Buddhist statues. Suspects were arrested but later released on bail.

Three months later, Sri Lankan security agencies received a tip-off from Indian and United States intelligence agencies that the NTJ may be preparing to carry out terrorist acts against churches, but the crucial information was not passed to Sri Lanka's Prime Minister, Ranil Wickremesinghe.

Since the attacks, the Sri Lankan Government has apologised for failing to act on the intelligence brief.


Sri Lankans living near St Anthony's shrine run for safety after police found explosive devices in a parked vehicle, which later exploded in Colombo. Photo / AP

'The threat is real': Islamic State calls for revenge after Christchurch attack

Last month, the New York Times reported Abu Hassan al-Muhajir, the spokesman for Isis, broke six months of silence to call for retaliation after 50 Muslims were killed in the Christchurch attacks on March 15.

After the threat, Kiwi security expert Dr Paul Buchanan, director of 36th Parallel Assessments, said with Isis fighters returning to their home countries after defeat in Syria "the threat is real".

However, the level of threat depended on how New Zealand responded as a nation and rallied around its Muslim community, Buchanan said.

"Defeat in Syria is sending Isis fighters back to their home countries to resume decentralised, small-unit and lone-wolf operations against soft targets.

"Massacre gives them a recruiting tool and incentive [revenge]. The threat is real.

"But New Zealand may be safe if the non-Muslim population rallies around the Muslim community.


"How we respond as a nation will determine the level of threat."

Yesterday Buchanan told the Herald it was unlikely the Sri Lanka bombings were retaliation for the Christchurch attacks.

He said given the co-ordinated nature of the attacks and intel warnings which were ignored, it would seem a month was too little time to prepare for such an attack.

"Christchurch seems to be a convenient justification for something that was being planned before March 15 and has more to do with ethnic-religious conflict in Sri Lanka," he said.

"It does show the dangers of tit-for-tat responses to terrorist attacks of any stripe, as it feeds into the 'clash of civilisations' narrative."

- Additional reporting from the Telegraph.