The clash began when a group of militants attacked a security check post and a police station in Mattani area.
Four policemen, including an officer, were injured in the assault. The two sides exchanged fire for several hours.
An armoured personnel carrier was damaged in the attack.
The injured policemen were taken to the Lady Reading Hospital.
Four militants were subsequently killed in reflationary action by the security forces.
In a separate incident, the bomb disposal squad defused two bombs planted in Bara Sheikhan area of Peshawar.
