A roadside bomb targeted a police van on the outskirts of this northwestern Pakistani city on Friday, injuring three policemen, officials said. The van was on a routine patrol when the bomb planted along the Ring Road went off on Friday morning. Officials described the condition of one of the three injured policemen as serious. No group claimed responsibility for the attack. Police sealed off the area and blocked the road to traffic. Security forces in Peshawar have been on high alert after suicide attacks on a Shia procession in Lahore killed nearly 40 people on Wednesday.