From correspondents in Islamabad, Pakistan, 04:30 PM IST

At least 11 people, among them four students and five policemen, were killed when a bomb exploded in a tribal area of northwest Pakistan 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 Thursday, a blast also took place near heavy-guarded police complex in Pakistan's capital, injuring at least ten people.

(Staff Writer, © IANS)