A powerful roadside bomb struck a police vehicle in a former stronghold of the Pakistani Taliban in the restive northwest of Pakistan bordering Afghanistan on Wednesday, killing at least two officers and wounding 14 others, mostly passersby, officials said. The attack took place in the city of Wana in South Waziristan, a district in the Khyber Pakhtunkhwa province, according to local police chief Adam Khan. Militant violence has surged in recent weeks, claiming the lives of dozens of security personnel.