COLOMBO, Sri Lanka - Soldiers attacked Tamil Tiger rebels in Sri Lanka with tanks, mortars and artillery in fighting that killed 23 guerrillas and seven soldiers, the military said Sunday.

Troops backed by helicopter gunships pushed across northern front lines Saturday and destroyed eight rebel bunkers, said military spokesman Brig. Udaya Nanayakkara.

The fighting killed 10 rebels and four soldiers, he said, adding that another 10 soldiers were wounded.

On the same day soldiers and rebels nearby fought separate gunbattles that killed 10 guerrillas and two soldiers, Nanayakkara said.

In other fighting army troops destroyed a rebel bunker and killed three guerrillas on the northern Jaffna peninsula, he said.

Separately, insurgents detonated a roadside bomb Saturday near the southeastern town of Buttala, killing one soldier and wounding another, Nanayakkara said.

Rebel spokesman Rasiah Ilanthirayan could not immediately be reached for comment.

It was not possible to independently verify reports because the government restricts access to northern areas where the conflict is raging. Both sides routinely exaggerate their opponents' casualty figures and underreport their own.

The rebels have been fighting since 1983 for an independent state in the north and east for Sri Lanka's minority ethnic Tamils, who were marginalized for decades by governments dominated by the majority Sinhalese. The conflict has killed more than 70,000 people.

Reports of fighting have increased in recent months amid government promises to capture the Tamil Tigers' de facto state in the North and to crush the rebel group by the end of the year. Diplomats and other observers have said the army was facing more resistance than it expected.

Fighting has escalated in the past two years and worsened further after the government announced in January that it was pulling out of a tattered cease-fire signed by the government and rebels in 2002.