As many as 13 vehicles were destroyed in the blast. The explosion also caused damage to nearby shops, offices and homes.
About two hours later, a blast hit a preaching centre in Mingora town of Swat in northwest Khyber Pakhtunkhwa province, 115 km from Islamabad.
Hundreds of people had gathered inside the preaching centre for Friday prayers when the explosion went off, killing at least 22 people and injuring 65 others.
Initial reports said it was a gas cylinder blast, but officials later said a bomb was planted in the basement of the centre.
