Apparent Afghan insider attack kills NATO troops KABUL, Afghanistan A man wearing an Afghan police uniform shot and killed two British soldiers at a checkpoint in southern Afghanistan on Tuesday, international military officials said. The assault appeared to the be the latest in a string of insider attacks that have threatened the partnership between international troops and the Afghan forces they are trying to train to take over responsibility for the country's security. A statement from the NATO military coalition said only that the assailant was wearing a police uniform, leaving open the possibility that the attacker was a militant posing as a policeman. The statement did not provide details on the shooting, saying it was being investigated. The British Ministry of Defense said the attack happened at a checkpoint in Helmand Province's Nahri Sarraj district. "The loss of these soldiers is a huge blow," Maj. Laurence Roche, a spokesman for British troops in Helmand, said in a statement. The two killed soldiers were with the 1st Battalion The Royal Gurkha Rifles, he said. At least 53 international troops have been killed in attacks by Afghan soldiers or police this year, and a number of other assaults are still under investigation, the international alliance has said.