Colombo: Tamil Tiger rebels ambushed and killed four village policemen in the restive northern district of Vavuniya before dawn today, the military said, the latest in a spree of deadly attacks on security forces in the area. The fatal shootings come after a rash of land and sea clashes, ambushes and air raids that have killed an estimated 4,500 people since last year alone.

The terrorists attacked a homeguard post near Vavuniya town, killing four of them a spokesman for the Media Centre for National Security said, declining to be named in line with policy. Homeguards are a force of police recruited and armed to guard their own villages and wear a distinct light purple uniform.

The town of Vavuniya is the last major staging post before the southern front line that separates government from rebel-held territory in the north. Fighting has now shifted to the far north, where the Tigers run a diminished de facto state after losing vast swathes of territory in the east in the face of military advances in recent months. There are now daily clashes of killings amid a new chapter of a two-decade civil war that has killed nearly 70,000 people since 1983,and analysts see no clear winner on the horizon and fear the conflict will grind on for years.