COLOMBO - Government forces pushed into Tamil Tiger-held territory in embattled northern Sri Lanka on Saturday after a fierce, daylong battle that reportedly resulted in dozens of casualties.

The Sri Lankan military says 30 guerrillas and six soldiers have died in the fighting.

The Liberation Tigers of Tamil Eelam rebel group claims it killed 30 soldiers and wounded 75, while losing only three over its own fighters.

Fighting has increased sharply in recent weeks, with the government vowing to retake rebel-controlled areas and crush the Tigers after more than two decades of warfare.

But diplomats and other observers say the army has faced stiffer resistance than expected.

The Tamil Tigers have been fighting since 1983 for an independent homeland for minority ethnic Tamils, who complain of widespread discrimination at the hands of the country's Sinhalese majority.

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

In the latest offensive, infantry troops moved into Mannar district backed by artillery and mortar fire, said military spokesman Brig. Udaya Nanayakkara.

Heavy fighting killed 30 rebels and six soldiers. Fifty-one guerrillas and 25 soldiers were wounded, he said.

It was not possible to independently verify either side's claim because journalists are barred from the conflict zone. Both sides commonly exaggerate their enemies' casualties while underplaying their own.