The island's prime minister has underlined fears that the ethnic Tamil guerrillas could be planning to celebrate with a bang, following the discovery in recent weeks of two trucks, each crammed with around a tonne of explosives.

"The explosives in the truck were enough to destroy half of Colombo," Ratnasiri Wickremanayake told reporters shortly after the first truck bomb was found before it was detonated.

In their northern de facto state, the Tigers will light coconut oil lamps and hold Hindu services for at least 260 rebels -- more than a quarter of them women -- who have blown themselves up in the name of an independent homeland.

The first of these "Black Tigers" was a rebel known as Captain Miller, who drove a truck bomb into an army camp in the Jaffna peninsula on July 5, 1987, killing 40 soldiers.

Meanwhile, four suspected Tamil Tiger rebels and three soldiers were killed in fresh violence in Sri Lanka's embattled north, military officials said yesterday.

Tamil Tiger guerrillas set off a powerful roadside blast in the district of Vavuniya Tuesday, killing the three soldiers, military officials said.