The bus, empty of all but the driver, blew apart outside a train station, ripping the fronts off buildings and shredding dozens of vehicles. The dead included at least three children from schools in the area and two police officers as well as the driver, police and defence ministry spokesmen said.
Books, a plastic lunch box and children's shoes were strewn near an overturned van at the scene. Hundreds of injured were rushed to Colombo's main hospital, and weeping parents rushed to the area to try to account for their children.
Nobody immediately claimed responsibility, but police superintendent Palitha Perera said: "It definitely looks like the work of the Tigers." The Liberation Tigers of Tamil Eelam are the main separatist force on this island nation and have been fighting since 1983 for a homeland in Sri Lanka's north and east.
A defence ministry spokesman said the driver of the bus had disregarded a stop sign at a police checkpoint, prompting police to give chase. The bus "mowed down" a policewoman who had tried to stop it He said the bus's route would have taken it down the road used by government ministers on their way to parliament, which was in session.
Lokuarachchige Sriyawathie, hit in the left arm and face by flying glass, had come to the neighbourhood to pick up his son from school. "Just as we got to the school gate, there was a huge explosion and I was knocked down by the blast," he said.
Phone lines in the city were jammed as residents sought information about the blast.
The explosion, which could be heard a kilometre (half-mile) away, occurred just after noon at the intersection of several of the city's busiest streets and near a police station. The front of the train station was badly damaged, and the police station slightly damaged. At least 40 vehicles were destroyed and about 50 shops were damaged.
The Secretary-General of the United Nations, Kofi Annan, expressed outrage at the bombing. "Once again, the secretary-general condemns, in the strongest possible terms, the use of violence against civilians. Terrorism cannot be condoned in any circumstances," a statement read by a UN spokesman said. The statement called for an end to the armed conflict in Sri Lanka and extended condolences to the families of the victims.Reuse content