A superintendent of police killed while four others sustained serious injuries in a suicide attack on a police van at Peshawar, officials said on Thursday."Police Superintendent Rural Kalam Khan died in the blast and his driver and a guard was injured," police officer Tahir Ayub told the media added that the explosion took place in in Pashta Kharra Chowk."The bomber came on foot and detonated explosives strapped to his body near SP Khan jeep," bomb disposal squad chief Hukum Khan said."We have found the bomber s head," he added.The van was standing between Ring Road and Pusht Khara Chowk. The injured cops were taken to Lady Reading Hospital for treatment.While confirming suicide attack, Additional Inspector General Squad Shafqat Malik informed that evidences had been gathered while cordoning off the attack area.Police officials said that SP Rural Kalam Khan had played a brave role in operation against terrorism in the province resulting in decrease of suicide attacks in Peshawar and adjoining areas.While giving tribute to deceased SP Kalam Khan, provincial information minister Mian Iftikhar Hussain said that his sacrifice would not be spoiled.Talking to media at blast site, he said back bone of terrorists has been broken and these militants were attacking on security forces with their remaining power.Mian Iftikhar reiterated that war against terrorism would continue until the last terrorist remains alive.