Colombo, Feb.3 : At least seven people were killed and 100 were injured on Sunday in a suicide bomb attack onboard a train at the main railway station here, police and hospital sources said.

The BBC put the death toll at eight.

A police spokesman said the attack was carried out by a suspected rebel Tamil Tiger woman suicide bomber as a suburban train pulled into the station in the heart of Colombo.

"Train services have been stopped and the injured have been rushed to the main hospital with six critically hurt," said police spokesman, N. Illangakoon.

The attack comes amid increased security ahead of celebrations on Monday to mark the 60th anniversary of Sri Lanka's independence from Britain.

On Friday, 18 people died in a blast in the central town of Dambulla.

Both attacks have been blamed on Tamil Tiger rebels.

The rebels, who have been fighting for an independent state in the north and east since 1983, have carried out frequent suicide and bomb attacks in the city and other areas.

The civil war has intensified since last month, when the government pulled out of a ceasefire with the rebels.

The scene of the blast has been cordoned off.

The Colombo railway station is situated in the heart of the city, near the president's offices and several major hotels.

Huge parades have been planned in the city, large parts of which have been closed off.

A bomb attack on the city zoo earlier on Sunday injured four people.The blast, near an aviary, is thought to have been caused by a grenade.

ANI