MIRANSHAH: Suspected militants ambushed vehicles carrying police officers in a remote northwestern region of Pakistan near the Afghan border on Saturday, injuring four of them, a security official said. The attack happened on a road between Mir Ali and Miran Shah in the North Waziristan tribal region, a day after the military said it had killed between 15 to 20 militants. The official, who spoke on the condition of anonymity, said the injured officers had been transported to a hospital, where two of them were in critical condition.