Unidentified gunmen have killed five health workers in an attack in north-west Afghanistan, officials say. A doctor and several nurses were among those killed in the attack on a clinic in Badghis province late on Sunday, governor Enayatullah Enayat said. Meanwhile in southern Helmand province, three people, including two policemen, have been killed in separate incidents. Violence has risen sharply in recent months, with a string of suicide attacks, mostly in Afghanistan\'s south. It was not immediately clear who was behind the attack on the health centre in a remote part of Badghis province. \"This clinic was essential for this area. It was the only health care there,\" Mr Enayat told the Associated Press news agency. He said the assailants had set fire to health centre. The two policemen killed in Nawa district of Helmand province died in an explosion while on a poppy eradication patrol, provincial police chief Gen Abdul Rahman Saber said. In other violence in the province, Taleban militants attacked two trucks taking food and water supplies to the American base in Greshk district. One of the drivers was killed while the other is reported missing, Amanullah, a senior provincial police officer, told the BBC. (BBC)