Rauff Hakeem, leader of the opposition Sri Lanka - Muslim Congress, said they are collecting evidence to file a suit to overturn the election.

Health Minister Nimal de Silva dismissed the opposition's complaints.

``We would most welcome such litigation because we can prove beyond any reasonable doubt before the court that the elections were free and fair,'' he said.

He said there were a few minor incidents, but nothing that would have affected the outcome of the vote. Discuss this story Published: Mon May 12 07:50:19 EDT 2008

The fighting took place Monday, mainly along the front lines surrounding the rebels' de facto state in the north.

In the worst battles, five rebels were killed in a morning fight with troops in the Vavuniya district, while five others were killed in a clash hours later, the military said.

Seven other rebels were killed in other battles, it said.

Tamil Tiger gunmen also shot two police officers killing one in the eastern district of Batticaloa, which had been controlled by the rebels until the government ousted them last year, the military said.

Rebel spokesman Rasiah Ilanthirayan did not answer a phone call seeking comment.

It was not possible to independently verify the military's claims because reporters are not allowed in the war zone.

The two sides are known to exaggerate casualties inflicted upon the other and play down their own losses.

The Tamil Tigers have fought since 1983 to create an independent homeland for ethnic minority Tamils who have been marginalized by successive governments controlled by majority Sinhalese. More than 70,000 people have been killed in the violence. Published: Tue May 13 08:18:28 EDT 2008

The country's once admired democratic institutions are buckling under the strain. It is worth recalling that the LTTE emerged in the late 1970s against a backdrop of mounting grievances in the north and east of the island country over declining access to language, employment and political rights. A radical leftist group, the People's Liberation Front (JVP) - composed primarily of disgruntled Southerners - raised similar concerns, albeit from a different perspective.

The response of the Sri Lankan government to these grievances was as swift as it was severe. It has waged a virtually uninterrupted military campaign against the LTTE since the early 1980s. For its part, the LTTE, a merciless armed group, has engaged in brutal attacks against civilians as well as assassinations of their opponents, raising support and money in the Tamil diaspora, including the large community in Canada. A conservative estimate puts the number of deaths in the fighting at 75,000. The government also launched aggressive operations against the JVP and about 60,000 civilians died over a two-year period in the late 1980s before the JVP made its transition to politics. More... Published: Mon May 12 09:39:17 EDT 2008