Security personnel began chasing a vehicle after its driver refused to stop at a check post in Sharifabad area early this morning.
The man then blew up the explosives-laden vehicle, killing himself and five security personnel who were chasing the car, police officials said.
Several persons were injured by the explosion.
Witnesses said the powerful blast shook nearby buildings.
Law enforcement agencies cordoned off the area and found three grenades and a pistol at the site of the blast.
No group claimed responsibility for the attack.