Colombo  - The Sri Lankan Navy destroyed a medium-sized vessel carrying a large quantity of military hardware for Tamil rebels in a pre-dawn raid off north-eastern Sri Lanka, Defence Ministry spokesman Brigadier Udaya Nanayakkara said Saturday.

The vessel was spotted and confronted off Mullaitivu, 410 kilometres north-east of the capital, he said.

Four more boats attempting to provide escort to the rebel vessel were also sunk in the same area, he said.

Nanayakkara said that initial warnings were given for the vessel to stop, and instead the Navy was fired on, prompting the Navy to destroy the ship.

The vessel, with a length of approximately 30 to 40 metres, was engulfed in a ball of fire and sank, the Navy said.

The incident came as government troops backed by the Sri Lankan Air Force stepped up operations against Tamil rebels in the northern province after fierce fighting earlier in the week.

The military said that at least 120 rebels and 25 soldiers were killed and 10 soldiers were reported missing in the confrontations in the Kilinochchi district. Tamil rebels claim that more than 170 soldiers were killed in the battles.

The Sri Lankan military has been facing stiff resistance from the rebels as they attempt to enter the stronghold of Kilinochchi, 370 kilometres north of the capital.

Earlier, the government had vowed to crush the rebels before the end of 2008. (dpa)