At least 23 people have been killed in a bomb blast near Colombo, the Sri Lankan capital, police say.

Thirty more people are said to have been wounded in the explosion which ripped through a crowded bus on Friday.

Brigadier Udaya Nanayakkara, a spokesman for the military, said: "There is an explosion in [the suburb of] Piliyandala. The explosion is in a bus."

He blamed the attack on fighters from the Liberation Tigers of Tamil Eelam (LTTE), a separatist group seeking a state in the north of the country.

Carnage

A police official at the scene said: "At least three people died on the spot."

He also said that 15 people had been taken to the nearby Kalubovila hospital. The bus burst into flames after the explosion and the death toll is expected to rise.

No group has come forward to claim the attack.

Al Jazeera's Minelle Fernandez, reporting from Colombo, said it has been a violent week in the country.

She said: "Unfortunately this has culminated in many civilian deaths."

Fernandez also said that since the end of the ceasefire between the LTTE and the Sri Lankan government, a wave of attacks have occurred.

Continued violence

"Even before the truce had officially ended, violations of the agreement were common. Now, both sides have no obligation to this agreement, making the situation considerably worse, reflected through the rising death toll," she said.

A similar blast in February wounded 18 people aboard a bus.

In the same month, suspected LTTE fighters used a parcel bomb to blow up a crowded bus in northern Sri Lanka, killing at least 20 people.

The LTTE, also known as the Tamil Tigers, are fighting for independent homeland in the country's northeast.

PHOTO CAPTION

Sri Lankan soldiers patrol in the Jaffna peninsula on April 6, 2008.

Al-Jazeera