Eleven people, including six policemen, were killed and 16 others wounded in a Claymore mine blast, suspected to have been triggered by Tamil Tiger rebels, in eastern Sri Lanka on Wednesday.

The mine, planted near an electricity transformer, was targeted at a bus taking constables home on leave, a police official said.

"Six policemen were killed along with four soldiers, who were providing them with security," the official said, adding: "A civilian was also killed and 16 others were wounded."

Security forces had on January 19 captured the main Tiger stronghold of Vakarai town where they maintained a de facto separate state for over 10 years.