QUETTA: Armed motorcyclists killed a police head constable by indiscriminate firing in Sariab here Monday. According to details Head Constable Manzoor Ahmed was moving in his vehicle in Killi Faizabad Sariab here today. Miscreants sprayed bullets on him in which he died on the scene. Miscreants ran away from the scene. Police registered a case and started their search. Dead body was shifted to civil hospital.