The bus with 30 people onboard caught fire after the blast in one of a five  gas cylinder and 13 passengers died of burn wounds.

Correspondents at the scene said The injured were shifted to hospitals by the police rescue teams. While casualties might increase due to serious wounds. .

The bus was destroyed in the blast. Traffic on the main highway between Rawalpindi and the eastern city of Lahore was suspended after the blast.

TV footage showed the burnt body of the bus.

Further detail including nature of explosion was awaited, he added.