Sri Lankan security forces and Tamil Tiger rebels exchanged artillery fire today along a de facto frontline in the northern peninsula of Jaffna.

The rebel Liberation Tigers of Tamil Eelam (LTTE) and the army exchanged fire across the Muhamalai-Nagarkovil frontline in the peninsula, the pro-rebel Tamilnet.com website said. It said the military had retreated from some of their frontline positions and the Tigers had advanced a "significant distance."

However, military spokesman Prasad Samarasinghe denied any guerrilla advance. "There is a misinformation campaign by the LTTE. We have not moved back an inch," Samarasinghe sai said the main entry and exit point for civilians going to the government-held part of the Jaffna peninsula remained open despite the early morning fighting.

There were no immediate reports of casualties on either side. However, in the island's eastern province, a policeman was shot dead by the Tigers this morning, the military said. The clashes came despite a truce that has been in place since February 2002.

The war in Lanka | More reports from Lanka