A senior Tamil-speaking minister and 11 others were killed and over 90 injured in a powerful suicide bombing at a ceremony marking the start of a marathon race as part of Sri Lanka's [Images] traditional New Year celebrations near Colombo, officials said.

The incident, blamed by the government on the Tamil Tigers, occurred at the western district of Grampaha, about 25 kms from the capital Colombo, where Minister of Highways and Road Development, Jeyaraj Fernandopulle, was attending a function to mark the Sinhala and Tamil New Year.

Fernandopulle, a vocal critic of Tamil Tigers, was about to wave a flag to start a marathon race when the bomb went off at the Kanthi playground in Weliveriya town of the district.

The minister, regarded as a potential prime minister-in waiting, died of injuries sustained in the blast at a hospital, officials said.

They said 11 others, including former Olympic marathoner K A Karunaratne and national athletic coach Lakshman de Alwis, were also killed in the suicide blast.

Over 90 people, including Grampaha police Senior Superintendent Hector Darmasiri, were seriously injured in the blast and rushed to a local hospital, the Defence Ministry said while blaming the Tamil Tiger rebels for the blast.

Fernandopulle, who was a Sri Lankan delegation member in the failed peace talks with the Tamil Tigers, has become the second minister to have been assassinated this year.

D M Dassanayake, Minister for Nation Building, was killed in a bomb blast in the same district on January 8, days after the government pulled out of a ceasefire with the Tamil Tigers.

Fernandopulle, a Roman-Catholic, was a senior figure in the government. He first became a member of Parliament for the Sri Lanka Freedom Party in 1983 and served in several ministerial roles since 1997. He practised as a lawyer before joining politics.

Television footage showed people screaming and running through the bloodied path after the powerful explosion went off near the minister as he addressed the athletes.

Condemning the attack as a 'cowardly' act of the Liberation Tigers of Tamil Eelam, President Mahinda Rajapaksa appealed for calm.

"While calling on the people to be calm and collected in the face of such extreme provocation by the forces of terror, I wish to reiterate that this dastardly act will not weaken our resolve to eradicate terrorism from our midst, and bring peace, harmony and democracy to all our people, which was also and unqualified wish of Mr Jeyaraj Fernandopulle," he said in a statement.

K Sivanesan, an MP from pro-rebel Tamil National Alliance, was also killed in a roadside bomb attack this year, for which both government and LTTE blamed each other.

The fighting between the Sri Lankan security forces and the rebels has escalated in the island's embattled north since the government pulled out of the Norwegian-brokered ceasefire.

The LTTE has been fighting for autonomy for minority Tamils in island's north and east. At least 70,000 people have died since the war began in 1983.