A suicide attack targeting a prison van wounded at least 10 policemen in Pakistan's restive northwest on Saturday, officials said. "The bomber blew up his explosives-packed car near the van, wounding 10 policemen, two of them seriously," senior police official Shakil Ahmad told AFP. Nobody was in the van at the time of the attack, in the town of Timergara in Lower Dir district. "We have found the engine of the car used in the attack and some body parts of the bomber including his sliced head from the site," Ahmad said. Another senior police official, Qazi Jamil, confirmed the incident, saying: "It was a suicide attack targeting the police van." A campaign of suicide and bomb attacks has killed nearly 3,300 people in less than three years across the nuclear-armed country of 167 million, blamed on Al-Qaeda, Taliban and other extremist Islamist groups. Under US pressure, Pakistan has in the past year significantly increased operations against militants in its tribal belt.