Awwal 28, 1432 H/March 3, 2011, SPA -- A powerful explosion near a small police building in a residential area of Pakistan's troubled northwest killed at least four people and wounded 30 on Thursday, police said. According to AP, the attack happened in the Hangu area, just outside the tribal regions where al-Qaida and Taliban fighters have long operated, said senior police official Rasheed Khan. The blast also damaged several homes. Most of the victims were civilians and were rushed to hospitals, Khan said. Security and government offices are routinely attacked by militants in Hangu, which is part of the Khyber-Pakhtunkhwa province.