Updated

Pakistani police say gunmen have opened fire on a vehicle carrying a senior police officer in the southwestern city of Quetta, killing two of his guards but the officer escaped unhurt.

Abdur Razzaq Cheema, police chief in Quetta, said the target of Wednesday's attack was Hameedullah Dasti. He was en route to a prison to take militants on trial to court. Dasti was traveling in a bullet-proof vehicle, but the guards were not.

No one immediately claimed responsibility for the attack.

Quetta is the capital of Baluchistan province, the scene of a low-level insurgency by Baluch separatist groups that demand a greater share of the province's resources.

Militant groups also operate there and often target police.