Five students were killed and more than 50 other people injured when a bomb ripped through a bus heading to a university in south-western Pakistan today, police said.
The attack happened in the city of Quetta, the capital of Baluchistan province.
Police declined to say who they suspected in the latest blast in the region, which is frequently hit by acts of violence.
Islamist militants often attack security force or government targets, as do separatist rebels, who also kill settlers from other parts of Pakistan. Sunni extremists also frequently kill Shiites in the region, sometimes pulling them off buses and gunning them down.
The bus targeted today was heading to the Baluchistan University of Information Technology in an upmarket area of Quetta.
Police officer Mir Zubair Mahmood said five students on the bus were killed and scores were wounded, as were several passers-by.
Police initially said it was a motorcycle bomb, but later said it was a car bomb that was detonated remotely.