Police detained 10 people for questioning overnight after a bus bomb near the Sri Lankan capital killed six, and authorities strongly suspect separatist Tamil rebels in the blast, the Defense Ministry said Saturday. The bombing Friday occurred on a busy highway in Nittambuwa town, 40 kilometers northeast of Colombo. Thirty more passengers were wounded in the blast. "Combined security operations during the night were carried out in the area and 10 people were detained for questioning," military spokesman Brig. Prasad Samarasinghe said. "At least 2 kilograms of explosives were used in the blast, and investigations ... strongly link the blast with the terrorists," Samarasinghe said, referring to the Tamil Tiger rebels.