Karachi: In a brazen assault, gunmen donning police uniforms attacked a bus carrying Shia Ismaili community members and shot the passengers in the head, killing at least 47 people in Pakistan's southern port city of Karachi, the latest in a series of terror attacks targeting minorities.

Police officials said it appeared that six to eight assailants on motorbikes first opened fire on the bus just near the Dow Medical College and then entered the bus when it stopped at Safoora Chorangi, Gulistan-e-Johar area of Karachi.