In the last week of June, Sri Lankan police recovered a huge stash of arms and explosives in the eastern town of Kattankudy from where Zahran Hashim, the alleged mastermind of the Easter bombings, hailed. It included some 300 gelignite sticks, 1,000 detonators, and nearly 500 T56 live ammunition. The recovery reportedly shocked investigators, who had made considerable progress in their probe of the April 21 attack that claimed over 250 lives.

The search operation was based on information from Mohamed Milhan, one of the five suspects deported from Saudi Arabia earlier in June. Currently in custody, Milhan was a likely heir to Zahran Hashim. “It was an eye-opener, really,” a top official, familiar with the probe, told The Hindu.

“The material would have been enough for another 25 suicide attacks,” the official said, requesting anonymity, given the sensitivity of the investigations. “A crucial source” is how the official described Milhan, who reportedly tried to join the IS but was unsuccessful. A resident of Kattankudy, he left Sri Lanka on April 17, days before the attacks.

The seizure of weapons and explosives based on his clue, seen along with earlier confiscations, has given “a different direction” to the investigations, according to the senior official.

Days after the Easter blasts that suicide bombers carried out at churches and hotels in capital Colombo and in the eastern district of Batticaloa, troops raided a safe house on the island’s east coast. In addition to explosives, they seized dozens of white dresses, usually worn by Buddhist women for temple visits or prayers, sparking concern over possible future attacks targeting Buddhists.

While all main suspects, including family members of the suicide bombers, are under custody and heightened surveillance continues across the country, investigators are wary of dismissing the possibility of a “lone wolf attack”. “We have to be very vigilant,” the official said.

Meanwhile, criminal investigations into the Easter attacks are “nearly complete”, according to officials, who are awaiting forensic reports from government analysts and foreign experts, who have been supporting the investigation. By end of the month, they hope to submit a report to the Attorney General’s Department, so that prosecutions can be initiated.

With all key suspects are under custody, and details of suicide bombers compiled, investigators are piecing together other information to establish how the individuals linked up and maintained their network.

Deadliest incident

The Easter day bombings were the deadliest incident in Sri Lanka in its relatively peaceful post-war decade. The country’s economy, particularly the tourism sector, is struggling to recover from the shock and impact after three months.

Over 1,00,000 tourists arrived in July, but it is still a 46.9% drop compared to July last year, according to data provided by the Sri Lanka Tourism Development Authority. However, hotels and malls are gradually beginning to draw more people, and Sri Lankans and tourists are able to travel across the country.

In addition to the CID’s probe, a presidential committee is investigating the Easter blasts, as is a parliamentary panel that has been collecting testimonies from top security officials, bureaucrats and political leaders.

Earlier this week, Prime Minister Ranil Wickremesinghe, the top most official to appear before the parliamentary committee, said he was yet to get a “satisfactory response” on why he was not briefed about the prior intelligence available with the authorities.

Top security officers knew of a possible terror threat, but both President Maithripala Sirisena and Mr. Wickremesinghe have maintained they did not know.

Multiple accounts from investigators suggest that the IS, which belatedly claimed the attacks, was not directly involved. Local Islamist radicals carried out the terror operation, officials have said.

“In fact, even the suspects in custody are telling us that Zahran had only a small group to start with. He was able to recruit more youth only after the anti-Muslim riots in Digana in 2018,” the senior official said.

Meera Srinivasan is The Hindu’s Colombo correspondent.