Colombo  - A suicide bomber killed at least five paramilitary guards and injured 10 others on the outskirts of Colombo Sunday, military spokesman Udaya Nanayakkara said.

The suspected Tamil rebel attacked detonated himself at a paramilitary guard post located in Wattala, 10 kilometres north of the capital.

The incident came hours after the Sri Lanka navy destroyed a Tamil rebel boat and killed at least four rebels off the northern coast, a navy spokesman said.

The naval attack took place off Point Pedro, more than 400 kilometres north of the capital, shortly after Saturday midnight.

Government troops have intensified military operations against the Tamil insurgents in the north. (dpa)