Police say a handicapped woman blew herself up Wednesday morning after security personnel stopped her from entering the offices of Social Welfare Minister Douglas Devananda in Colombo. One of his staff members was killed and two others were injured. The woman, who was apparently wearing a bomb vest, also died.
The woman had been allowed into the complex with other people who had come for a weekly open meeting to discuss their problems with the minister - the apparent target of the attack.
Devananda heads a party representing Sri Lanka's Tamil ethnic minority (the Eelam People's Democratic Party). He once fought alongside the Tamil Tiger rebel group, but renounced violence and joined the political mainstream in 1987.
Police have blamed Wednesday's attack on the rebels, officially known as the Liberation Tigers of Tamil Eelam, or LTTE. The attack came just a day after the LTTE chief, Vellupillai Prabhakaran, said in an annual radio address that peace efforts with the Sinhalese-dominated government are a waste of time.
He described the government as "genocidal", and accused it of aiming to destroy the Tamil community.
Political analyst Rohan Edresinghe of Colombo's independent Center for Policy Alternatives says the message from the rebel chief is clear: there is no hope of a political settlement between the government and the rebels.
"The LTTE will now try to show the Sri Lankan government and show the world that they have military strength, they have military prowess, and that they cannot be defeated militarily," he said.
Prabhakaran blamed the international community for fueling the conflict by giving the government economic and military aid.
The conflict has intensified since a 2002 peace agreement began to unravel three years ago. Earlier this year, the government scored a major military success against the rebels by driving them out of their eastern bases.
Observers say the Tigers are also under pressure in their northern bases. They say the government is intent on pressing its military advantage instead of pursuing peace talks.
The Tamil Tigers launched their struggle for a Tamil homeland in 1983. The conflict has since claimed more than 60,000 lives.