A huge explosion today rocked Karachi, leaving four peoplekilled, including a senior police officer, while several others were injured. Pakistanisecurity sources said that the bomb blast targeted the residence of senior policeofficer Shafiq Tanoli at a vegetables market, which left him dead along with of hisrelatives.The same sources said that fifteen other people escaped with injuries in Old SabziMandi area. Police cordoned off the scene of the explosion for investigation, whilethe dead and the injured were taken to hospitals.