The army is trying to take the rebel-held town of Sampur, from where the rebels are in artillery range of a major naval base and able to disrupt a key maritime supply route to the besieged army-held northern Jaffna peninsula.

"We are trying to neutralise the threat to Trincomalee," said a military spokesman. "Our strategy is to send people into Sampur to neutralise their artillery and mortar positions which are pointed towards the harbour."

He said 14 soldiers had been killed and 92 wounded since the offensive began on Sunday. The army estimates around 120 rebels were killed. The Tigers were not immediately reachable.

Officials said more than 20 lorries carrying government aid had been allowed into rebel territory through a 'border' crossing in the northern district of Vavuniya since Thursday.

The Essential Services Commission was loading 3,600 tonnes of emergency aid and food purchased by shop owners to sail to the northern Jaffna peninsula, which is cut off from the rest of the island by rebel lines and where shop shelves are empty. It was expected to sail on Sunday.

Residents in Jaffna said the peninsula had been quiet for the past 24 hours after fierce artillery exchanges between the rebels and the military.

The main opposition party has agreed to help find ways to halt the renewed civil war.

Opposition leader Ranil Wickremesinghe wrote to President Mahinda Rajapakse saying he was ready to discuss ways "to resolve the national issue", party officials said. Previous collaborations have come to nought, and the Tigers trust neither side.

Rajapakse met British Prime Minister Tony Blair in London on Thursday to discuss lessons learnt from Northern Ireland's peace process.