About 25 000 Sri Lankans have escaped from a Tamil Tiger-held area in the north of the country, the army says.

The military said the people fled after the army broke through a fortification which had been blocking its advance into the Tigers' last stronghold, the BBC reported Monday.

The UN estimates that up to 100 000 civilians remain in the area, which has seen heavy fighting for months.

The Red Cross (ICRC) says government doctors working in the area are "worn out" and do not have enough supplies.

Each side accuses the other of killing civilians in the long running civil conflict.

Foreign reporters are not allowed into the combat zone, making it impossible to independently verify the claims.

Military spokesman Brigadier Udaya Nanayakkara said the army had managed to smash through an earth fortification which had been blocking its advance into the tiny coastal strip held by the rebels.