Sri Lanka's air force pounded a Tamil Tiger rebel training camp and supply base deep in the northern jungles on Sunday, a day after a fierce sea battle destroyed six rebel boats, the military said.

The airstrike was part of the government's intensified offensive against the guerrillas' de facto state in the north. Officials have pledged to crush the rebels by the end of this year.

Air force spokesman Wing Commander Janaka Nanayakkara did not provide details of damage or casualties at the training camp and logistics facility in northern Mullaitivu district, but said the pilots confirmed they had "hit the target accurately."

It is difficult to contact rebel officials for comment because most communication lines to their territory have been severed.

The airstrike came a day after a sea battle between the navy and the Sea Tigers, the naval wing of the Tamil guerrillas, off the northern Jaffna peninsula.

The military said the navy destroyed four rebel boats, killing 14 rebels, while air force planes destroyed two more boats and killed three more rebels. Five sailors were wounded in the fighting, it said.

However, the rebel-affiliated TamilNet Web site said rebel suicide fighters sank two navy vessels and damaged another. Seven rebels were killed in the mission, it said.

With reporters banned from the war zone, the media must depend on government and rebel statements for most information about the war.

Fighting has escalated in recent months in the 25-year-old civil war as the military has captured a series of rebel bases and large chunks of territory in the north.

The Tamil Tigers have fought since 1983 to create an independent homeland for ethnic minority Tamils, who have suffered marginalization at the hands of successive governments controlled by ethnic Sinhalese.

More than 70,000 people have been killed in the violence.