Colombo: Four people were shot dead in fresh Sri Lankan violence yesterday, while the killing of six Sinhalese farmers by suspected Tamil Tiger rebels the previous day raised fears of more ethnic riots.

Some 100 people have died in just over two weeks after a series of suspected Tamil Tiger ambushes on the military were followed by attacks on Tamil civilians.

Both sides say they are still working towards talks that were scheduled for last week in Switzerland, but are now indefinitely postponed. But diplomats say the peace process seems deadlocked and some fear a return to the island's two-decade civil war.

In eastern Sri Lanka, troops shot dead two suspected rebels setting up a fragmentation mine ambush, the army said. One soldier was wounded.

An explosion in the northern town of Jaffna hurt no one, but two Home Guard troopers were later shot dead in Vavuniya, another own in Sri Lanka's north.

An army spokesman said troops had increased their presence around the village where six farmers were shot dead late on Sunday, in the northeastern district of Trincomalee.

The Liberation Tigers of Tamil Eelam (LTTE), whose campaign for a Tamil homeland has killed more than 64,000 people on both sides, accuse the almost exclusively Sinhalese army of "ethnic cleansing" in the island's northeast, as well as increasingly frequent murders of Tamil civilians.

There is no doubt deaths are occurring, but analysts say it is the Tigers who are deliberately provoking confrontation to pressure the government in the knowledge that deeper ethnic divisions will drive more Tamils to their side.

"They want to say to the Tamils, we are your protectors," said Jehan Perera, national director for think-tank the National Peace Council. "And they want to create a Sinhalese backlash that will ultimately help them."

In Trincomalee district, some Tamil villages are already completely abandoned. Tamil civilians load their belongings on to bullock carts, fleeing to schools or into LTTE territory where they say they feel safer.

But the diplomatic process of bringing the two sides to talks remains deadlocked over the much smaller issue of arranging the transport of eastern rebel leaders to a pre-talks meeting in their de facto capital, Kilinochchi.

The Tigers want a military helicopter to transport their leaders; the government has offered first a ship, then a small civilian helicopter, and now a larger civilian helicopter.

Diplomats say neither side has been flexible enough.