A Pakistani police officer says an explosion at a mosque belonging to the country's Shiite Muslim minority has killed at least two people and wounded 15.

Dawood Khan says the explosion, which occurred on Friday afternoon in the northwestern city of Peshawar, was followed by gunfire that is still going on.

Pakistani television showed frantic images of people running from the area as thick smoke billowed, and ambulances taking the wounded away.

Peshawar has been the site of frequent militant attacks, including an assault on a school that killed 150 people, most of them schoolchildren.