The Taliban shot and killed six people working for a demining company in western Afghanistan, police said on Thursday, a day after the United Nations said the number of civilian casualties in the country jumped by a quarter in the first half of 2014. "The Taliban killed six de-miners from the Halo Trust landmine clearance organisation while they were on an operation in Kohsan district of Herat. They abducted three people," said Abdul Rauf Ahmadi, a spokesman for the provincial police chief. "The de-miners started their trip very early in the morning and hadn't informed the police," Ahmadi said, adding that a manhunt was under way to rescue the three abducted workers. The United Nations has documented 4,853 civilian casualties in Afghanistan, including 1,564 civilian deaths and 3,289 injuries, in the period between Jan. 1 to June 30. In southern Zabul province, four policemen were killed by three of their colleagues overnight. The rogue policemen have since defected to the Taliban with guns and a police vehicle. "The incident took place in Jaldak district of Zabul. An investigation is under way," Zabul deputy governor, Mohammad Jan Rasoulyar, told Reuters.