Sri Lanka's military says more than 30 Tamil Tiger rebels and one soldier were killed in a series of battles along the front lines in the country's north since Friday.
The military says the fighting took place in the districts of Mannar and Vavuniya, and at two places on the Jaffna peninsula.
There has been no immediate comment from the rebels about the latest military claims.
On Friday, the military accused the rebels of killing 10 civilians in a village southeast of Colombo, a relatively calm region of the country.
Violence has intensified in Sri Lanka since the government two weeks ago formally pulled out of a 2002 cease-fire agreement with the rebels, saying Tamil Tigers had used the truce to regroup and rearm.
The government says the military has forced the rebels out of their territory in the east in recent months and is now focusing on the rebel-held north.
Tamil rebels have been fighting for more than two decades to create a homeland for Sri Lanka's minority Tamils in the country's northern and eastern districts.
Some information for this report was provided by AFP, AP and Reuters.