At least four people have been killed and more than 20 wounded in a bombing by suspected Tamil rebels in the Sri Lankan capital of Colombo. The bomb attack came a day after a prominent Tamil lawmaker was shot to death. As Anjana Pasricha reports from New Delhi, the separatist conflict raging in the north of the country is increasingly being felt in the capital.

Sri Lankan army soldiers stand guard at an explosion site in Colombo, Sri Lanka, 02 Jan 2008

Officials say an army bus carrying wounded soldiers to a hospital was the target of the powerful roadside bomb that exploded Wednesday morning in a busy commercial district of Colombo.

At least one soldier died as the explosion shattered the bus and others were wounded. Several civilians in the vicinity were also killed or wounded in the attack.

Military spokesman Udaya Nanayakkara blamed the explosion on Tamil rebels, whose official name is the Liberation Tigers of Tamil Eelam, or LTTE.

"The LTTE, due to the desperation and due to the pressure applied to them in the north, they are trying to resort to this kind of terrorist activities in Colombo," he said.

Just a day earlier, a lawmaker from the ethnic Tamil community, T. Maheswaran, was shot dead by a gunman as he attended a New Year service in a Hindu temple in Colombo.

His party says the government is responsible because it had lowered his security protection. Maheswaran was highly critical of the government's military campaign against the rebels, and had blamed paramilitary troops for a spate of abductions and unlawful killings in the north, where the rebels are based.

The latest incidents of violence in Colombo came as fighting intensifies between the military and the rebels.

Human rights groups say political killings, abductions and bomb attacks have been on the rise in the past two years, since a cease-fire collapsed and the two sides resumed armed hostilities.

The director of Colombo's Center for Policy Alternatives, Paikiasothy Saravanmuttu, says all sides share the blame for the rising violence in the country.

"This is reflective of the total breakdown of the rule of law as far as the country is concerned and the viciousness with which the ethnic conflict is being carried out," said Saravanmuttu. "Invariably the finger points at the LTTE, or any of the other armed Tamil groups, and indeed allegations also are made against the government and its security apparatus."

The rebels are fighting for an autonomous homeland for the ethnic Tamil community. The government has vowed to crush the rebels on the battlefield, and clashes in the north are reported daily.