A policeman, escorting the electoral staff in a bus, shot an assistant presiding officer dead and injured two others following a quarrel with them in the limits of Makli Police Station on Sunday, officials said. Abbas Arain killed Pir Bux with his kalashnikov rifle and injured Ali Nawaz Bharani and Ghulam Rasool Jhokhio, they said. Meanwhile, dozens of teachers blocked the National Highway to protest the incident and demanded deployment of army for their security. District Police Officer Dawood Junejo has announced Rs 300,000 for the heirs of the deceased and Rs 50,000 each for the injured.