Colombo - Government troops were closing in on a Tamil rebel stronghold in northern Sri Lanka Wednesday, military officials said.

Troops were heading towards Mallawi, a town that served as an administrative centre for Liberation Tigers of Tamil Elam (LTTE) rebels, 290 kilometres north-east of the capital, a Defence Ministry statement said late Tuesday.

Parts of Mallawi town were captured on Monday, but more areas surrounding the town needed to be captured to take control of the area, it said.

Mallawi is a commercial hub on a main north-south artery, which intersects with several LTTE supply routes. A Tamil rebel office was found in the captured town, the ministry said.

In eastern Sri Lanka, a police officer and a paramilitary guard were killed in a rebel ambush on Tuesday.

The incident took place in Pothuvil, 360 kilometres south-east of Colombo. The government took control of the region earlier in the year, but sporadic incidents yet occur.

Sri Lanka's government believes that LTTE has about 5,000 fighters left. (dpa)