At least five people have been killed and 19 others wounded in northwest Pakistan after a car bomb exploded in a tunnel late on Friday.

The explosion occurred in the Kohat tunnel, a busy thoroughfare that connects the main northwest city of Peshawar to southern Khyber Paktunkhwa, Punjab and Sind provinces, Pakistani police reported.

Many of those wounded in the explosion were taken to medical facilities in Peshawar, the nearest large city. The blast also damaged the tunnel.

Northwest Pakistan has witnessed numerous bombings over the past years.

No one has as yet claimed responsibility for Friday's explosion.

Most attacks in the region are generally believed to be linked to al-Qaeda and Taliban-led groups.

The two-kilometre long tunnel has been the scene of past fighting between Pakistani security forces and the Taliban.

Source: Agencies