A gas leak in the van, en route to Dera Ismail Khan had caused the fire.
The van collided with an oncoming truck, injuring two persons in the vehicle, the police said.
Traffic on the Indus Highway was suspended soon after the incident, the police said.
At least nine people had lost their lives on Sunday after a passenger van fell into a ravine in Azad Kashmir’s Mirpur city.
The vehicle fell in Pir Gali area, killing nine and wounding six people, rescue sources said. Women and children were reported to be among the dead.
The injured were shifted to District Headquarter Hospital.
On June 1, at least seven people were killed and 30 injured during a traffic accident in the Safdarabad area of Nankana Sahib.