Fifteen people including six children were killed in Sri Lanka on Friday when suspected Islamist militants blew themselves up in a raid, police said.

The raid occurred in Sainthamaruthu, near the hometown of the suspected ringleader of the Easter Sunday attacks that killed at least 250 people.

Gunmen opened fire as troops attempted to raid a house, police said.

Three men set off explosives, they added, killing the children and three women. Three others died in gunfire.

One civilian was caught in the crossfire and died, according to police, while a wounded woman and child were taken to hospital.

Footage shown on state television showed charred bodies inside the house, one cradling a rifle. Explosives, a generator, a drone, and batteries were also visible.

Around the same time, security forces raided another building in a nearby town where they said they found explosives and a drone.

Some 600 Muslims fled the area as the raid unfolded and took shelter in a school, residents said.