Colombo  - Over 250 Tamil rebels were killed in overnight fighting in northern Sri Lanka as the country's military gained full control of the last rebel stronghold in northern Sri Lanka, the Defence Ministry said Sunday.

The stronghold known as Pudukudirrippu, 390 kilometres north-east of the capital, was taken Sunday after pitched battles around the area overnight, the Defence Ministry added.

Some key leaders of the Liberation Tigers of Tamil Eelam (LTTE) rebel group were said to be among the 250 killed, a number that brings the rebel death toll to more than 400 since April 1, the ministry said.

A reporter based in the area for state-run television said the last remaining rebels were believed to have slipped into a 20- kilometre zone declared as a safe zone for the estimated 50,000 to 150,000 civilians residing there.

The army has vowed to gain control of this area as well, the reporter said.

The military has been fighting for weeks to gain control of the Pudukudirrippu area which is located on the western side of the costal safe zone.

The Defence Ministry said troops are now positioned to make further tactical moves into the remaining territory to free hundreds of civilians held hostage by the LTTE. dpa