Thousands have fled Sri Lanka's northern war zone in recent days, crossing the front lines amid fierce fighting, the military said on Friday.
Assault signals Tamil Tigers are turning to guerrilla tactics as government closes in on rebel-held territory.
Sri Lankan attack helicopters bombed Tamil Tiger positions on Saturday, a day after ground forces seized the rebel headquarters town of Kilinochchi.
Sri Lankan troops marched into the Tamil Tigers' de facto capital of Kilinochchi and the town is about to fall to the government , an official said.
Simultaneous army attacks on Tamil Tiger defences in Sri Lanka killed 120 guerrillas and 25 soldiers on Tuesday, the military said.
For Tamils erecting lifesized posters to mark the forthcoming Heroes' Day, when Tiger rebels remember their fallen, the election of Mahinda Rajapakse as new Sri Lankan president is a matter of concern. "We know Mahinda. He has been a politician for a long time. And we don't trust him," said Daruniali Saravanam, owner of a roadside eatery outside Kilinochchi, political capital of the rebels.