The men set off explosives after an hour-long gun battle with police yesterday, inside what was believed to be a jihadist hideout near the eastern town of Kalmunai, in the latest fallout from the Easter attacks.
In a statement posted yesterday by the Daesh propaganda unit the Amaq News Agency, Daesh said the three men were part of the Daesh group and detonated their bombs after the fight with police.
The statement said the men “clashed with them (Sri Lankan police) with automatic weapons, and after exhausting their ammunition, detonated on them their explosive belts.”
Fifteen people died in the clashes, police said, including three women and six children, AFP reported.
The violence came six days after the Easter Day bombings on three churches and three luxury hotels which killed at least 253 people and injured 500.
Security forces armed with emergency powers have stepped up search operations for extremists since the bombings.
Kalmunai is in the same region as the home town of Zahran Hashim who founded the group accused of staging the attacks.