On Sunday, an election meeting addressed by UNP leader Ranil Wickremesinghe was bombed, killing two and wounding more than 40 people.

Both leading candidates called for an end to the violence and appealed for a peaceful election.

"We want to complete the work we have started ... we want to establish peace," Ms Kumaratunga said after filing her nomination papers.

"We ask everyone to support the government to hold a peaceful election," she said.

Her main rival echoed her words.

"On 21st December I will take this country to the 21st century," Mr Wickremesinghe declared.

"We have seen enough of violence. It is time to say enough is enough. We appeal to all for a peaceful election," he said.

Violence

The poll comes in the wake of heavy fighting in the north between Sri Lankan forces and Tamil Tiger separatist rebels.

Analysts have suggested that heavy losses suffered by the military at the hands of the Tamil Tigers could hurt Ms Kumaratunga's chances of re-election.

The president has called for a peaceful election

The UNP has accused the government of masterminding violent attacks on the opposition.

Three UNP activists were hurt when gunmen opened fire on a party office near the election commission in Colombo.

"Forty-two rounds were fired at our office," UNP legislator Ravi Karunayake told reporters.

Supporters of the ruling party were also blamed for defacing and pulling down opposition posters and cut-outs along the route to the election commission.

Only cut-outs of President Kumaratunga were left standing.

On Monday, the UNP asked for extra security for Mr Wickremesinghe, after his narrow escape the previous day.

Ms Kumaratunga's ruling People's Alliance faces its main challenge from the UNP, but the radical left JVP (People's Liberation Front) could come into play in the event of a close contest.

Sri Lanka's minority Tamils did not field a candidate after failing to arrive at a consensus on a common contender.