Clashes between rival factions of the Tamil Tiger rebels in eastern Sri Lanka left at least four guerrillas dead, a military spokesman said Sunday. The two separate clashes Saturday night occurred in areas controlled by the mainstream rebel group in Tharavai, 250 kilometers (155 miles) east of the capital, Colombo, Brig. Daya Ratnayake said. «We are still gathering reports, but our intelligence sources say that there were four fatalities,» Brig. Daya Ratnayake said. He said all those killed belonged to the mainstream rebel group. The two rebel factions split a year ago. Recent killings have threatened a three-year cease-fire between the government and the guerrillas. The Tamil Tigers began fighting a civil war in 1983 to create a separate state for ethnic minority Tamils, accusing the majority Sinhalese of discrimination. About 65,000 people were killed before the Norway-brokered cease-fire. Peace talks broke down a year later when the Tigers withdrew, demanding wide-ranging autonomy in the Tamil-majority northeast.