Seven people have been killed in a mine explosion in northeastern Sri Lanka on Friday, local police said.

Four civilians and three military personnel were on a commuter bus when the blast occurred in the district of Trincomalee. Another six people were reported as injured.

No one has yet claimed responsibility for the attack. However, local authorities blame the Tamil Tiger militants, who have been fighting for an independent state for 25 years.

Fighting has intensified recently with government troops conducting a large-scale ground operation against the Tamil Tigers in northern Sri Lanka.

More than 80,000 people have died in the conflict since 1983.