Troops and rebels had exchanged heavy weapons fire in Jaffna peninsula. Elsewhere in the north air force jets flew over rebel-held territory.

The BBC says the island's four-year-old ceasefire exists only on paper and there is a very real chance of war.

The two sides blamed each other for starting the recent shelling in Jaffna's Nagarkovil area.

Tamil rebel

Military spokesman Brig Prasad Samarasinghe confirmed the sorties over rebel-held territory, saying the air force had been flying over Sri Lankan territory. There were no reports of air strikes.

The truce has disintegrated over the last six months, with daily violations and escalating violence.

A bus bombing, in which at least 64 people were killed, began the latest round of fighting. The rebels denied carrying out the attack.

The government says it wants to engage the Tigers in talks and address the root causes of the conflict.

It said the discussions could be with or without the Norwegian facilitators who brokered the truce.

The rebels have been fighting for an independent Tamil homeland for over two decades. More than 60,000 people have died.