The attack took place at a police station.

"Four policemen and two civilians were wounded after a suicide bomber blew up his car at the checkpoint," senior police official Nisar Ahmad Tanoli told AFP.

The blast damaged the outer wall of the police station and two houses near the checkpoint, he said.

Taliban immediately claimed responsibility for the attack.

"We carried out the suicide attack on the police station... we will not spare them and target them again," Taliban spokesman Ehsanullah Ehsan told AFP on phone from an unknown location.