QUETTA, Pakistan (AP) -- Pakistani police say a car bomb attack on a police truck has killed at least four policemen and two civilians in the southwestern city of Quetta.
Abdur Razzaq Cheema, the police chief in Quetta, says 22 people were also wounded, several critically.
Wednesday's attack took place in the Saryab Road area of the city. Cheema says an investigation is underway to determine whether it was a suicide bombing or the explosives-laden vehicle was detonated remotely when the police truck was passing by.
The police chief says the death toll from the attack could increase.
No group immediately claimed responsibility for the attack.
Quetta is the capital of Baluchistan province, which has been the scene of a low-level insurgency by Baluch separatist groups. Islamic militants also operate in the region.