Sri Lankan troops killed 11 Tamil separatists in several gunbattles across the volatile northern region, the military said on Wednesday.
Reports of fighting have increased in recent months amid government promises to capture the rebels' de facto state in the north and crush the group by the end of the year. But diplomats and other observers say the army is facing more resistance than it had expected.
A defense ministry official said the latest fighting took place Tuesday along the front lines that separate government-controlled territory and rebel territory in the north. He spoke on condition of anonymity because he was not authorized to speak to the media.
Army troops killed six guerrillas in the Vavuniya district, just south of rebel-held territory, and in the nearby Mannar district, another five rebels died, the official said. He said the clashes wounded four soldiers.
Another two battles wounded 16 rebels and one soldier, he said. Rebel spokesman Rasiah Ilanthirayan could not immediately be reached for comment.
It was not possible to independently verify the military's claims because journalists are banned from the war zone. The government and rebels often exaggerate the other side's casualties and underreport their own.
The rebels have fought since 1983 for an independent homeland for ethnic minority Tamils, who have been marginalized for decades by successive governments run by majority ethnic Sinhalese. More than 70,000 people have been killed in the violence.