KARACHI: A Sunni Tehrik (ST) worker was killed and three were injured in a clash between Sunnis and Shias in the city on Tuesday. The clash took place with activists of the Naad-e-Ali in Jaffar-e-Tayyar Society, Malir, police said. A group of Shias gathered outside Farooq-e-Azam mosque and tried to burn down a board with the names of the caliphs, police said, adding that this led to an argument between the management of the mosque (belonging to the ST) and the Shia group. An unidentified man shot at the mosque's management during the argument, killing Mukhtiar, an ST worker, and injuring ST workers Zubair, Amjad and Nazeer.