May 10, Colombo: An underwater explosion ripped through an empty merchant vessel that was moored at the Trincomalee harbour in eastern Sri Lanka in the pre dawn hours of today.

The Sri Lankan navy said the MV Invincible A-520 logistic vessel sank due to the explosion adding that the rebels bombed the 213-foot cargo ship with an underwater explosion at about 2:15 a.m. "No lives were lost due to the explosion," the Defense Ministry said.

The Tamil Tiger rebels meanwhile claimed their Sea Tigers launched a pre-dawn attack while the ship was loaded with explosives to be transported for troops operating in the island's north.

Sri Lanka Navy said the A-520 was a merchant vessel built in 1970's and handed over to the Navy, following a court order after it was apprehended while transporting 254 illegal migrants off Tangalle in 2003.

The explosion follows a bomb blast earlier in the day in Ampara that killed eleven civilians and injured another 29 as the government is preparing to hold the provincial council elections in the Eastern region. Defense analysts say the Tigers are desperately trying to disrupt the polls and to show that they haven’t lost their power in the region despite the claims by the Sri Lankan government that the region is liberated.