Two factions of the Tamil Tiger rebel group are staring each other down across a river in eastern Sri Lanka, threatening to fight after an unprecedented split in the rebel group. The tension comes as Sri Lankans prepare to vote in an election largely aimed at getting the country's peace process back on track.

A ferry crosses between the banks of the Verugal River in eastern Sri Lanka - the frontline in the standoff between the two factions of the Tamil Tigers rebels.

On one bank are soldiers loyal to Vellupillai Prabhakaran - the military leader of the Tamil guerrillas since the group was formed in the 1970's. He is based in Jaffna, in northern Sri Lanka. His troops along the river, mostly boys in their teens, halfheartedly dig trenches along the bank.

On the other side are soldiers loyal to Colonel Vinayagomoorthy Muralitharan - known as Colonel Karuna. He split last month from Mr. Prabhakaran's troops to form his own eastern command, based in the district of Batticaloa. About 6,000 of the Tiger's 15,000 fighters left with him.

The river is less than 100 meters wide, and the guerrillas on each side eye each other suspiciously - but so far no fighting has broken out.

Colonel Karuna's brother - known by the nickname Reggie, commands the troops along the river. He says the split was a long time coming.

He says that more than 2,200 fighters from Batticaloa have been fighting and dying in Jaffna. He says the eastern forces have contributed lives and materiel for this war, but the leaders in Jaffna do not give them enough respect.

The rebel leaders are known for their tight control over their forces and intolerance for dissension. Now, many Sri Lankans worry that the Tamils' factional strife not only could spill over into the general population, but also that it could disrupt efforts to end the island's long civil war.

The guerrillas have been fighting for greater rights for Sri Lanka's Tamil minority for more than two decades. An estimated 60,000 people have died in the fighting.

Peace talks between the guerrillas and the government have been stalled for a year. At the same time, a feud between President Chandrika Kumaratunga and Prime Minister Ranil Wickremesinghe over who should control the peace process has come close to derailing the talks completely.

On Friday, Sri Lankans vote in parliamentary elections that may give either the president or the prime minister a greater mandate for their strategies on ending the war.

Paikiasothy Saravanamuttu, with the Center for Policy Alternatives, a Colombo think-tank, says no matter what its outcome, the internal rift has damaged the Tamil Tigers.

"They are really on the horns of a dilemma," he said. "Were it to allow Karuna to get away scot-free, or indeed to consolidate himself as an eastern, regional leader, etc, the organization will probably be perceived to become softer or weaker or whatever. ? On the other hand, were they to eliminate him, the argument would be, My God, these people really haven't changed."

The friction between the Tamil Tigers may have already taken its first victim.

Mourners wail as a coffin bearing the body of a Tamil parliamentary candidate who supported Colonel Karuna is brought into his family's home in Batticaloa. Witnesses say two men entered the home and shot dead the candidate and a relative before fleeing.

No one knows who the gunmen were - but mourners such as this man blame those loyal to Mr. Prabahkaran.

"Because we all are from Batticoaloa. There's a problem between Batticaloa and Jaffna people. This man from Batticaloa," a mourner explained.

Other Tamil leaders are on their guard.

Joseph Pararajasingham is a Tamil parliamentary candidate who backs Mr. Prabhakaran. He has received death threats and now has 10 bodyguards. But he says he will not back down.

"I told them I am prepared to die on principle rather than on regional issues And I die as a martyr of principle - not for anything else," he said.

Local media report that Tamils from Jaffna have begun to leave Batticaloa to return to the north in fear of more violence between supporters of Colonel Karuna and Mr. Prabhakaran.

Commander Reggie's frontline troops say they are prepared to defend themselves if attacked. But if the factions do start fighting, it could well spread past the river banks, and across the country, making it hard to stop.