Colombo - Government troops backed by air support Thursday recaptured a town held by Tamil rebels in northern Sri Lanka, having killed more than 50 rebels, a military spokesman said.

Paranthan town, located 385 kilometres north of the capital Colombo was seized in the early hours of Thursday after heavy fighting overnight, the military said.

The town is the gateway to the northern Jaffna peninsula. Its capture is strategically important to the security forces as it cuts off a main rebel route, the spokesman said.

At least 50 rebels of the Liberation Tigers of Tamil Eelam (LTTE) were killed and twice the number were injured in the fighting, the military said, but made no mention of whether government troops had suffered casualties.

Government troops are now making their way towards the last two key rebel strongholds - the districts of Kilinochchi and Mullaitivu. Parts of the two districts have already been captured.

Tamil rebels claimed that four civilians were killed and 16 others were injured in airstrikes on Wednesday in a village close to Paranthan.

The pro-rebel Tamilnet website said that air force bombers had dropped bombs on a civilian settlement causing the casualties, a claim denied by the air force.

A public appeal has been made by the government calling all civilians to leave the rebel-held areas and enter areas controlled by the army where they would be put up in camps, but so far only about 1,000 people have responded to the call.

Some 350,000 civilians have been displaced due to the fighting, but rebels have not permitted civilians to leave, refugees said.

The government earlier vowed to crush the rebels by the end of last year, but heavy monsoon rains in November and rebel resistance has delayed the offensive.

Since military operations were launched in August 2006, government troops have captured areas in the north and east of the country.

The military claims to have killed over 12,000 rebels and said it lost some 2,500 soldiers. However, there has been no independent confirmation of figures given by the military. (dpa)