Forty Tamil Tigers and six soldiers have been killed in a series of battles along the "border" that separates state from rebel-held territory in northern Sri Lanka, the military said on Sunday.
Fighting in the latest phase of a 25-year civil war has intensified since the government scrapped a six-year-old ceasefire pact last month. It said the rebels were using the truce to re-arm.
"There was a series of clashes in Mannar which killed 11 terrorists and two soldiers, while confrontations in Vavuniya killed 19 terrorists and three soldiers also died," a military spokesman said, asking not to be named in line with policy.
Seven Tiger rebels and a soldier were killed in the northern Jaffna peninsula, while another three rebels were killed in the northern district of Polonnaruwa, he added.
Buoyed by battlefield victories in the east, where it has captured swathes of rebel-held terrain, the government is now seeking to overrun the rebels' northern stronghold and has vowed to defeat the separatist Tigers militarily.
But the Tigers continue to mount deadly suicide attacks and roadside bombings, including in the capital Colombo, and analysts say neither side is winning.