Islamabad, Pakistan (CNN) -- Nine people were killed in an explosion Wednesday in northwestern Pakistan, authorities said. Police suspect the blast on the outskirts of Peshawar targeted a vehicle carrying Pakistani air force officials, they said. Pedestrians and shoppers died, and three officers were among more than two dozen people injured, said government official Javid Marwat and Peshawar Police Chief Tahir Ayub. The explosion destroyed a van and nearby shops. Police are working to find out where the bomb was planted. Pakistani TV showed the wreckage of the van and emergency crews carrying away bloodied victims. Peshawar is the capital of Khyber Pakhtunkhwa province and the gateway to Pakistan's tribal region, which is largely ungoverned and has a strong militant presence. For more than a decade, Peshawar has been the front line for the Pakistani government's fight with militant groups.
NEW: Pakistani air force officials in a targeted vehicle were injured, officials say . Explosion also injures more than two dozen people . The blast occurs on the outskirts of Peshawar, Pakistan .