IS has claimed responsibility for coordinated bombings in Sri Lanka which killed 321 people and injured about 500 others, the group’s AMAQ news agency said on Tuesday.

“Those that carried out the attack that targeted members of the US-led coalition and Christians in Sri Lanka the day before yesterday are Islamic State group fighters,” said a statement released by IS propaganda agency Amaq.

The group did not give evidence for its claim.

The claims come at the same time as Sri Lanka’s deputy defence minister announced that an initial probe indicated the deadly suicide bomb attacks in Sri Lanka that killed more than 320 people were “retaliation for Christchurch”.

“The preliminary investigations have revealed that what happened in Sri Lanka (on Sunday) was in retaliation for the attack against Muslims in Christchurch,” state minister of defence Ruwan Wijewardene told parliament.

On Tuesday evening, the Sri Lankan Prime Minister Ranil Wickremesinghe told reporters that so far, only Sri Lankan nationals had been arrested but that there were “unfolding links” between the perpetrators and IS.

“There was a suspicion that there were links with IS,” he said. The Prime MInister added that there were still a “few people” on the run.

At least 321 people were killed in eight separate attacks on Sunday.

The explosions took place during busy Easter services at Christian churches in Negombo, Batticaloa and Colombo and in three five-star hotels in the capital. 

On March 15, a white supremacist gunman opened fire on worshippers in two mosques in Christchurch, New Zealand, killing 50 people in what was the country’s worst-ever mass shooting.

Mr Wijewardene said investigations showed that a local group called National Thowheeth Jama’ath (NTJ) was behind the attack and was linked to a little-known radical Islamist group in India.

“We believe [the massacre] was carried out by an extreme Islamist group as a reprisal to the Christchurch mosque massacre in New Zealand,” Mr Wijewardene said in a statement to parliament.

“This group is known to have links to an organisation named National Thowheed Jamath.

“We should take immediate steps to ban any such organisation that have links to extremist elements.

Mr Wijewardene told parliament the “National Thowheeth Jama’ath group which carried out the attacks had close links with JMI it has now been revealed” in an apparent reference to a group known as Jamaat-ul-Mujahideen India.

Little is known about JMI, other than reports it was established last year and is affiliated to a similarly named group in Bangladesh.

The minister said Sri Lanka was receiving unspecified international assistance with the investigation.

Two Muslim brothers were Sri Lanka hotel suicide bombers

Muslim brothers carried out two of the hotel suicide blasts in Sri Lanka on Easter Sunday, police sources told AFP on Tuesday.

The sons of a wealthy Colombo spice trader were among suicide bombers who hit three churches and three luxury hotels, investigators said. 

An attack on a fourth hotel failed and helped lead police to the Islamist group now blamed for the assault, they added.

The brothers, whose names have not been revealed, were in their late twenties and operated their own “family cell”, an investigation officer said.

The pair were key members of the Islamist National Thowheeth Jama’ath (NTJ) group which the government has blamed for the attacks, the official added.

One brother checked into the Cinnamon Grand hotel and the other the Shangri-La on Saturday.

The next morning, at virtually the same time, they went to the hotels’ Easter Sunday breakfast buffets and blew up explosives-laden backpacks, the officer said.

Another bomb tore through a restaurant at the nearby Kingsbury hotel. Minutes before, similar explosions devastated three churches. Investigators said it was not known whether the brothers were in contact with the other bombers.

Another would-be suicide bomber walked into a fourth luxury hotel in Colombo on Sunday, official sources told AFP.

“This man had also checked into the hotel the previous day,” the source said.

Fourth attacker

It was not known if his explosives failed or he had a change of heart.

But after the Shangri-la blast, the staff at the unnamed hotel became suspicious and the man was tracked to a lodging near the capital. He blew himself up there when confronted by police, the source said.

Two bystanders were also killed.

“What we have seen from the CCTV footage is that all the suicide bombers were carrying very heavy backpacks. These appear to be crude devices made locally,” the source said.

With 321 people confirmed dead, including at least 39 foreign nationals, and over 500 wounded, Sri Lanka has declared a state of emergency and launched a desperate hunt to head off more attacks.

At least 40 people were under arrest on Tuesday over one of the worst militant strikes ever staged in Asia.

The whereabouts of the brothers’ parents was unknown. But the blasts had a further impact on the family.

One brother gave false identity details when he checked into the hotel, the investigator said. The other gave a real address which led police commandos to their family home in a commercial area of Colombo.

Sri Lanka in mourning

Sri Lanka fell silent for three minutes on Tuesday on a day of national mourning to honour more than 300 people killed in suicide bomb blasts that have been blamed on a local Islamist group.

Flags were lowered to half-mast on government buildings, and people bowed their heads and reflected silently on the violence that has caused international outrage.

The silence began at 8.30 am, the time that the first of six bombs detonated on Sunday morning, unleashing carnage at high-end hotels and churches packed with Easter worshippers.

Shortly after the silence was observed, a police spokesman said the death toll had risen to 310, with several people dying of their injuries overnight.

The first memorial services for the victims, among them dozens of foreigners, were being held on Tuesday, hours after the government imposed a state of emergency and said an Islamist group was behind the violence.

At St Anthony’s Shrine in Colombo – where scores died as they gathered for Easter Sunday prayers – a few dozen people held candles and prayed silently, palms pressed together.

And at St Sebastian’s Church in Negombo, north of the capital, an elderly man wept uncontrollably by the coffin bearing the body of his wife. 

Police said that 40 people were now under arrest over the suicide bomb attacks – the worst atrocity since Sri Lanka’s civil war ended a decade ago.

The attacks were also the worst ever against the country’s small Christian minority, who make up just seven per cent of the 21 million population.

Tensions high

Tensions remained high and security heavy after a bomb discovered by police on Monday near one of the targeted churches blew up before police could defuse it.

Although there was a powerful blast, no injuries were reported. 

Police also found 87 bomb detonators at a Colombo bus station.

More details have begun to emerge about some of the foreigners killed in the blasts.

The United States reported at least four Americans killed – including a child – and the Netherlands raised their toll to three. 

A Danish billionaire lost three of his children in the attacks, a spokesman for his company said.

Eight Britons, eight Indians and nationals from Turkey, Australia, France, Japan and Portugal, were also killed, according to Sri Lankan officials and foreign governments.

The suicide bombers hit three Colombo luxury hotels popular with foreign tourists – the Cinnamon Grand, the Shangri-La and the Kingsbury – and three churches: two in the Colombo region and one in the eastern city of Batticaloa.

Two additional blasts were triggered as security forces carried out raids searching for suspects. 

Interpol said it was deploying investigators and specialists to Sri Lanka, and the US State Department warned of possible further attacks in a travel advisory.

Memories of civil war

Ethnic and religious violence has plagued Sri Lanka for decades, with a 37-year conflict with Tamil rebels followed by an upswing in recent years of clashes between the Buddhist majority and Muslims.

Burials were expected to begin for some of the dead on Tuesday.

At St Sebastian’s, the atmosphere was heavy with grief as coffins were brought in the grounds one at a time for services.

“There are so many bodies that we can’t accommodate them all at once,” Anthony Jayakody, auxiliary bishop of Colombo, told AFP.

The attacks have sparked local and international outrage, and have been condemned by Sri Lankan Muslim groups, with one urging the “maximum punishment for everyone involved in these dastardly acts”.