Aid workers stopped from leaving Sri.Lanka rebel base

COLOMBO, Aug 20 (Reuters) Dozens of aid workers have been stopped from trying to leave a stronghold of Sri Lanka's Tamil Tigers, colleagues said today, as the government prepared to ferry supplies to a northern enclave under siege.

A convoy of vehicles carrying 141 mostly local staff from foreign and local aid agencies was stopped as it tried to leave the Tigers' northern base of Kilinochchi, officials said.

The foes are locked in fierce fighting that many analysts say has effectively collapsed a 2002 truce and re-ignited a two-decade civil war. Shared borders separating rebel from government territory are shut most of the time, hampering the flow of aid and people.

''They are being stopped from leaving. We are not quite sure who is to blame,'' said one aid worker on condition of anonymity.

''Maybe to have humanitarian aid workers in Kilinochchi is a way to put pressure on the government.'' Rebel media coordinator Daya Master said the aid worker convoy was unable to leave because the crossing points into government areas were shut. He denied the Tigers were stopping them, and said they were free to go.

The military said it would allow the aid workers through if they are able to reach a crossing point in the north central district of Vavuniya.

The United Nations says 160,000 people have been displaced in Sri Lanka's northeast and dozens have been confirmed killed during over three weeks of fighting that has shattered hopes of sealing an end soon to years of ethnic strife.

The Tigers are furious at President Mahinda Rajapakse's refusal to consider their demand for a separate ethnic homeland for minority Tamils in the north and east, and each side accuses the other of trying to start a full-blown war.

However, there was a relative lull in fighting today, with only sporadic exchanges of artillery fire in the northern Jaffna peninsula.

The military said it hoped a ship carrying 4,000 tonnes of food aid and essentials would set sail for Jaffna, which is cut off from the rest of the island by Tiger territory and where food supplies are running out fast, as early as Monday.

Many foreign passport holders in Jaffna -- most of them expatriate Tamils -- are scrambling to register themselves for any eventual evacuation, and are appealing to be ferried out once aid has been offloaded.

REUTERS BDP PM2218