At least 11 people, among them four students and five policemen, were killed when a bomb exploded in a tribal area of northwest Pakistan on Thursday, Geo TV said quoting the police.
A police van carrying prisoners hit a roadside bomb in Upper Dir district of North West Frontier Province. A passing school van was also hit by the blast.
There was no further information about the attack, for which no group claimed responsibility.
Earlier on Thursday, a blast also took place near heavy-guarded police complex in Pakistan's capital, injuring at least ten people.