Three days after the bomb attacks in Sri Lanka that killed more than 350 people, investigators have come up with names of at least three suicide bombers – and a plot that stretches from Afghanistan to India and Bangladesh.

The attack has been claimed the Islamic State (ISIS), which posted videos of the suicide bombers swearing their bayat (allegiance) to ISIS on their official news channel, Amaq.

Intelligence sources say that Zahran Hashim was the key conspirator and lead bomber in the attacks. They have also identified Imsath Ahmed Ibrahim and his younger brother Ilham as two of the other suicide bombers.

They are still trying to identify the other suicide bombers who participated in the coordinated attacks on three churches and three hotels in Colombo and other cities on Easter Sunday.

Zahran Hashim’s name figured in an investigation carried out by India’s National Investigation Agency (NIA), when they were looking into ISIS activities in the southern Indian state of Tamil Nadu. The state has historical linkages with Sri Lanka, which has a 16% Tamil minority population.

Interrogation of one of the ISIS “sympathizers” in September and December last year led investigators to Zahran Hashim. After months of work, India passed on their findings to Sri Lankan intelligence officials on April 4 and 11, just before the attacks.

The failure of intelligence officials to act promptly and responsibly on those warnings – and alert the prime minister and cabinet – is now the subject of serious scrutiny. Zahran Hashim and other National Thowheeth Jama’ath members had been under close watch. Officials in both countries reportedly knew that NTJ had been stockpiling weapons and detonators and that Hashim and his close followers were plotting suicide attacks on churches.

But the Indian warnings were only shared with police in charge of “VIP security,” according to a New York Times report, which noted that President Maithripala Sirisena, who is in charge of security affairs and has been feuding with Prime Minister Ranil Wickremesinghe, had failed to provide “any satisfying answers about why security services did not do more to thwart the bombers.” Sirisena has appointed a committee to shine some light on those issues.

From Kerala to the Af-Pak border

In July 2016 Indian authorities reported that a number of young men and women had disappeared from the south Indian state of Kerala. This group, numbering 21 men and women, were believed to have been radicalized by Islamic State and sent to Nangarhar in Afghanistan to join an affiliate known as the Islamic State-Khorasan Province (IS-KP).

The IS-KP has been active in India’s southern states, plus Bangladesh, Sri Lanka and Maldives. It was initially headed by a Pakistani who was part of the Tehreek-e-Taliban Pakistan (TTP), the umbrella organization of Islamic militants in Khyber Pakhtunkhwa province near the Afghan border.

Some of the radicals from Kerala were believed to have been killed in an air strike by the US Air Force, while Indian intelligence officials worked with their Afghan counterparts to send others back home. In the middle of last year, three of the men returned to India and were arrested as soon as they landed. One of them, identified as “Basit,” told Indian investigators of an ISIS module working out of Coimbatore, a small town in the state of Tamil Nadu. In September the NIA raided several places based on revelations from “Basit.”

By December, the NIA had found links between the Coimbatore group and Hashim in Sri Lanka. They also recovered compact discs that had Hashim’s speeches, as well as call records going back and forth between Hashim and IS cadres in Bangladesh and Afghanistan.

The NIA also arrested six men, who shared more information on Hashim. India passed on these revelations to Sri Lankan authorities this month. Wickremesinghe told Indian news channel NDTV that they had received this intelligence. “India gave us the intelligence but there has been a lapse on how we acted on that … intelligence was not conveyed down the line,” he told NDTV.

Sri Lankan Prime Minister Ranil Wickremasinghe (center) visits the bomb damage at St Anthony’s Shrine in Kochchikade in Colombo on April 21, 2019. Photo: Ishara S Kodikara / AFP

The foot soldiers

Investigators have also located a copper factory where the bombs were assembled. They suspect that local materials were utilized to create explosives out of TATP (triacetone triperoxide). The owner of the copper factory, Inshaf Ahmed, is believed to be one of the suicide bombers, but that is yet to be confirmed.

All of the bombers are thought to have been associated with a local Muslim activist group called the National Thoweeth Jama’ath (NTJ) and acted as the foot soldiers of an “international network.” Indian investigators also found links to the NTJ while investigating another ISIS cell in Madurai, another city in Tamil Nadu.

Muslim residents in Kochchikade in Colombo, where one of the bombs exploded, have described the NTJ as a radical group with a different set of beliefs from theirs. Kochchikade, close to the port in the north of the capital, was where the first bomb went off at a Catholic church during mass on Sunday morning.

K M Akram, a resident of the area, told Asia Times that the Muslim community in Kochchikade were traditionalists. “We belong to the Tabliq Jama’ath [religious gathering, a non-political movement]. Our beliefs are different from these so-called members of the NTJ. They have made many attempts to come into our community, but they have failed. We do not trust them and they know they cannot break us apart from this community. Right now, even after the church attack, we are close to the families of the victims. We have helped the church and will continue to do so.”

Many others in the community believe that the NTJ is a small group of individuals with extremist beliefs. The shared sentiment of those in the Kochchikade area was that no such group is allowed in.

While relatively unknown, there were certain occasions where the group made headlines. A supposed secretary, Abdul Razik, of the group was arrested in 2016 for inciting sectarian violence. He was later released.

On Tuesday, Defense Minister Ruwan Wijewardene told a special session of Parliament that the motive behind the Easter Sunday attacks was to retaliate for the attack on Muslims in mosques in New Zealand a month ago.

“The preliminary investigations have revealed that what happened in Sri Lanka [on Sunday] was in retaliation for the attack against Muslims in Christchurch,” Wijewardene told Parliament.

While ISIS has not confirmed a connection to the massacre in New Zealand, it was noted that Sri Lankan Christians were part of a coalition led by the US against Muslims. Indian security officials believe that Sri Lanka was chosen because it is a “soft target.”