Bangladesh police say they have recovered a large amount of improvised explosive device from the hideout in Dhaka.

Dhaka, Bangladesh – At least two people blew themselves up on Monday after they were cordoned off by the security forces in a house in the Bangladeshi capital Dhaka, according to officials.

Before the “militants” killed themselves, they exchanged gunshots with Rapid Action Battalion (RAB) -Bangladesh’s elite police forces, Benazir Ahmed, the Director General of RAB, said at a press briefing in Dhaka.

Authorities in the South Asian nation had increased vigilance in the wake of Sri Lanka Easter Sunday bombings that killed more than 250 people.

“RAB fired about 150 rounds of bullets when they first started shooting at us,” said Ahmed.

“The bodies have been blown apart in the explosions. We will have to identify them through DNA profiling,” he said.

The police said that they have recovered “a large amount of improvised explosive device (IED) in the hideout”.

The RAB DG, however, said that there was no “full-proof” information about men’s identity and their affiliation with any “terrorist organisation”.

Human rights concerns

Acting on a tip-off about the presence of the banned Jama’atul Mujahideen Bangladesh (JMB) members, security forces cordoned off a tin-shed house in Metro Housing area of Basila on the outskirts of Dhaka.

RAB Additional Director General (ADG) Colonel Jahangir Alam told Al Jazeera that they first knocked the door but no one responded. “RAB fired back after gunshots were were fired from inside the house,” Alam said.

“Then there was a huge explosion at around 5am in the morning,” he said.

A total of four people, including the owner of the house, Wahab and caretaker Sohag, have been detained for questioning, the RAB ADG said.

Bangladeshi human rights lawyer Shahdeen Malik said the security forces should ensure that people in such cases are caught alive.

“Police or RAB or Counter-Terrorism Unit have always either killed the suspected militants or say that the militants have blown themselves up,” Malik told Al Jazeera.

He said Bangladesh in recent years has witnessed a number of extra-judicial killings. This (extra-judicial killings) doesn’t solve anything in the long run,” he said.

Steps should be taken towards finding the core problem of “militancy”, Malik said.

Bangladesh launched a crackdown on armed groups in the wake of 2016 deadly attack on a cafe in Dhaka that left 22 dead.

But human rights organisations have accused security forces of carrying out extra-judicial killings and enforced disapperarnces.