Suicide bombers cornered by security forces in a hideout in eastern Sri Lanka blew themselves up in a raid which left 15 people dead, including six children, police said Saturday.
A civilian was also killed in crossfire during the night-time raid near the predominantly Muslim town of Kalmunai, with hundreds of families later fleeing their homes.
Kalmmunai is in the home province of the jihadist suspected of organising the Easter Sunday attacks that left 253 dead.
Three men set off explosives killing three women and six children inside the house on Friday night, police said.
“Three other men, also believed to be suicide bombers, were found dead outside the house,” said a police statement. Police officials said all three were shot by security forces.
Gunmen opened fire on troops when they attempted to storm the house under cover of darkness, military spokesman Sumith Atapattu said.
An ensuing gun battle lasted more than an hour, a military official said, adding that the bodies were recovered following a search operation.
Charred bodies and at least one gunman cradling an assault rifle, were seen in video footage shown on state television.
Explosives, a generator, a drone and a large quantity of batteries were seen inside the house.
Some 600 Muslims fled a neighbouring settlement built to house displaced survivors of the 2004 Asian tsunami because of the fighting and took shelter in a school, residents said.
The civilian was hit in crossfire and died while a wounded woman and child were taken to hospital.
The operation followed a tip off that extremists linked to the Easter suicide bombings were holed up in Kalmunai, 370 kilometres (230 miles) east of the capital.
Zahran Hashim, founder of the National Thowheeth Jama’ath (NTJ) group blamed for the attacks and one of the Colombo suicide bombers, comes from the same province.
The clashes came hours after security forces raided a nearby location where they believe Hashim and other suicide bombers recorded a pledge of allegiance to Islamic State leader Abu Bakr al-Baghdadi before carrying out the bombings of three churches and three hotels.
Police said they found an IS flag and uniforms similar to those worn by the eight fighters in a video used by IS to claim responsibility for Sunday’s attacks.
“We have found the backdrop the group used to record their video,” the police said in an earlier statement.
The Islamic State group released their video two days after the bombings.
Police showed the clothing, the flag, some 150 sticks of dynamite and about 100,000 ball bearings seized from the house on national television.
Security forces armed with emergency powers have stepped up search operations for Islamic extremists since the bombings.