A new round of fighting in northern Sri Lanka killed 21 Tamil Tiger separatist rebels and two soldiers, the military said Tuesday.

The fighting, which took place Monday, was the latest in the island nation’s escalating civil war _ one marked by fierce ground and sea battles, air strikes, and bomb attacks that killed many civilians.

A statement issued by the military said the latest clashes broke out along fronts in the areas of Mannar, Vavuniya and Welioya around the guerrillas’ stronghold in the north.

Rebel spokesman Rasiah Ilanthirayan could not immediately be reached for comment and it was not possible to verify the military’s claims because reporters are not allowed into the war zone. Each side often exaggerates casualties for the other and plays down its own losses.

Also Monday, suspected Tamil Tiger rebels set off a bomb at a village in the government-controlled east, killing three policemen who were going to bathe in a river, the military said.

Two days earlier a roadside blast killed two police in the same area.

Government troops claimed last year that they had cleared the rebels from the country’s entire Eastern Province, but the insurgents still operate in scattered cells there and occasionally ambush the army and police.

Fighting is now concentrated in the north. The government has vowed to crush the rebels by the end of this year.

The Tamil Tigers have fought since 1983 to create an independent homeland for ethnic minority Tamils, who have been marginalized for decades by governments controlled by the majority ethnic Sinhalese.