Colombo - Troops in northern Sri Lanka located an airstrip used by Tamil rebels, military spokesman Brigadier Udaya Nanayakkara said Friday.

The airstrip was near a major irrigation tank in Iranamadu, of the Kilinochchi district, 370 kilometres north east of the capital, he said.

The Defence Ministry said troops reported the strip was 300 metres long and 15-20 metres wide.

"What we see here is more or less a conventional airstrip but adequate for a shorter liftoff," a military official was quoted by the ministry as saying.

Rebels of the Liberation Tigers of Tamil Eelam (LTTE) using Czech-built Zlin-143 aircraft have carried out nine attacks in the capital as well as on military establishments in the north and north-eastern regions.

Government troops have not yet found any aircraft. The rebels are believed to have at least three planes, but government troops have not yet found any of them.

Troops are advancing into the last rebel stronghold of Mullaitivu, 380 kilometres north-east of the capital, officials said.

The fighting is gradually forcing civilians out of the rebel-held areas. More than 1,000 people fled the conflict zones this week.

Government officials said more civilians were expected to arrive in the northern district of Vavuniya where arrangements are being made to accommodate the displaced. (dpa)