It was not immediately clear how he would celebrate his birthday, but he is expected to deliver his annual "heroes' day" address Saturday setting out the policy direction of his movement.

The run up to tomorrow's celebration is the ceremony honoring some 17,800 Tiger rebels killed in action since the first rebel was gunned down by security forces in 1982.

The Heroes' Week celebrations sparked tension between the Liberation Tigers of Tamil Eelam (LTTE) and the government forces across the island's embattled regions, according to both sides.

The defence ministry in a statement accused the LTTE of breaking the ceasefire and opening fire at security forces at Veppankulam in the island's north Thursday.

"The gunfire missed the target and hit a bus injuring two passengers," the ministry said in a statement. It also accused the Tigers of raising their flag in areas held by government forces in violation of the truce arrangements.

However, the LTTE denied opening fire and in turn accused the military of opening fire on civilians, injuring two. There were similar clashes between troops and civilians led by Tiger rebels in northern and eastern regions.

"The LTTE vehemently condemns these types of activities of the Sri Lanka armed forces that may tend to create a totally undesirable confrontational situation," the LTTE said referring to the skirmishes.

More reports from Sri Lanka