COLOMBO (AP): Sri Lankan naval forces backed by helicopter gunships attacked a group of rebel boats early Tuesday, sinking two and killing six Tamil Tiger sailors, the military said.

The sea battle came as the military pushed ahead with its multi-pronged offensive against the rebels' de facto state in the north.

The battle erupted in Nayaru Lagoon on Sri Lanka's northeast coast, just south of the rebel stronghold of Mullaitivu, when navy forces attacked seven Tamil Tiger boats, the military said in a statement.

The navy sank two rebel boats and severely damaged a third, killing six rebel sailors, the military said.

As the remaining rebel boats fled to shore to be hauled out of the water, attack helicopters pounded them with airstrikes, it said.