Sri Lankan government minister DM Dassanayake has been killed in a bomb attack. His car was peppered with shrapnel.
Soldiers kept guard while surgeons near Colombo battled to save the 51-year-old's life. Doctors said he suffered fatal head wounds.
At least one other person was killed and 10 injured in the blast, which closed the main road linking Colombo to the international airport.
The attack is the latest in Sri Lanka's escalating spiral of violence - more than 100 people have died this month, officials say.
Security forces have been on high alert since the government announced it was pulling out of a disintegrating ceasefire deal with Tamil Tiger rebels.
Correspondents say it is not clear who killed Mr Dassanayake. He had alleged underworld links, but was also a key member of the government, they say.