The Liberation Tigers of Tamil Eelam (LTTE) said they found the corpse of one soldier following the clash in Vavuniya district on Monday, and would make arrangements to hand over the body through the Red Cross on Tuesday.

There was no immediate comment from the military. The clash came five days after security forces captured a key Tamil rebel base in eastern Sri Lanka.

The LTTE have been fighting for a separate state for minority Tamils for 35 years -- a conflict that has claimed over 60,000 lives.

Meanwhile, unidentified gunmen shot dead a top civil servant in north-eastern Sri Lanka Monday as the government moved to celebrate the dismantling of a key Tamil rebel base in the region, officials said.

Gunmen killed Harry Abeyweera, the top civil administrator in the district of Trincomalee, as he worked at his office, police said. Gunmen escaped and an investigation was under way.

The assassination came hours after the government announced it will mark the wresting of the Eastern Province from the Liberation Tigers of Tamil Eelam (LTTE) after dismantling a rebel base in the district of Batticaloa.

President Mahinda Rajapakse condemned the killing and said it was a blow to restore democracy.

"This comes at a time when we are trying to restore democracy in the Eastern Province," a spokesman for the president said.