"We are expecting some kind of sabotage activity from the Tigers."

The US embassy advised American citizens to avoid unnecessary travel in and around the capital during the holiday because of fear of attacks.

Military might

Thousands of police and other security forces took up position in Colombo as the celebrations got under way with Mahinda Rajapakse, Sri Lanka's president, raising a national flag on the seafront.

Analysis


Sri Lanka crisis set
to worsen

A display of military might followed, with Rajapakse reviewing a parade of troops and tanks as fighter jets flew overhead.

The "challenge bestowed upon us by history is the defeat of terrorism," Rajapakse said in an address to the nation from Colombo's Galle Face road.

He said that the military now had the Tamil Tiger separatists cornered in the north of the island.

"We faced this challenge squarely without avoiding it. Our security forces are today achieving victories against terrorism unprecedented in history," he said.

Sri Lanka's government formally pulled out of a Norwegian-brokered truce with the separatists last month.

Bomb blasts

Early on Sunday, an electricity substation was destroyed by a bomb but there were no injuries, the military said.

A suicide bomber blew herself up at Colombo's
main railway station on Sunday [Reuters]
A more powerful bomb was found and defused in the same area several hours earlier, police said.

The military was already on high alert after three bombings over the weekend which were blamed on the Liberation Tigers of Tamil Eelam, which has been fighting for a separate homeland for the country's minority Tamils for more than two decades.

The suicide bombing at the capital's main railway station on Sunday was preceded by an attacks at the city's zoo which injured at least six people.

On Saturday, an explosion on a bus in the central town of Dambulla, about 150km northeast of Colombo, killed at least 18 people.