Sri Lankan troops and ethnic Tamil insurgents fought fierce battles around the island's embattled north Tuesday, leaving 145 combatants dead, the military said.

Military spokesman Brig. Udaya Nanayakkara said the clashes broke out in two villages in northern Jaffna peninsula and areas surrounding the insurgents' de facto capital of Kilinochchi, south of the peninsula.

Soldiers marched into the rebel territory in Kilali and Muhamalai villages early Tuesday, attacked their positions and returned to their bases, Nanayakkara said. Troops also fought heavy battles in villages surrounding Kilinochchi.

About 120 rebels and 25 soldiers were killed in the clashes and 10 more soldiers were reported missing, he said.

Rebels could not be contacted for comment because communication lines to their territory have been severed.

However, the rebel-affiliated TamilNet Web site reported that the insurgents killed 40 soldiers and 120 others on Kilali front alone. It did not report on rebel losses or details of other clashes.

Military spokesman Nanayakkara denied the TamilNet report.

It is difficult to verify battlefield reports released by the two sides because journalists are barred from the war zone.

Tamil Tigers have fought since 1983 to create an independent homeland for ethnic minority Tamils who have suffered marginalization by successive governments controlled by majority ethnic Sinhalese. More than 70,000 people have been killed in the violence.