A US soldier on camp in Afghanistan
Four soldiers fighting with the NATO-led alliance were killed in another suspected "insider" attack in southern Afghanistan on Sunday, the coalition said, bringing the total number of deaths this weekend caused by Afghans turning on their allies to six.
Four NATO-led troops were found dead and two wounded when a nearby response team arrived at the scene from a nearby checkpoint, a spokesman for the coalition said.
One of the six members of the Afghan National Police (ANP) operating the observation post with six coalition troops was also found dead, while the other five had disappeared, reports Reuters.
"The fighting had stopped by the time the responders arrived," said Major Adam Wojack, a spokesman for the NATO-led coalition.
Sunday's shooting took place in Zabol, a province where U.S. forces are based, according to a local official, who said all four soldiers killed were American.
The attack came a day after two British soldiers were shot dead by an Afghan policeman while returning from a patrol in southern Helmand province, one of the strongholds of the Taliban-led insurgency.
At least 51 foreign military personnel have been killed in "insider" attacks this year, deaths which have put a heavy strain on trust between the coalition and Afghanistan as they move towards handing security responsibility to Afghan forces by the end of 2014.
The rise in such attacks has led to the training of new recruits to the Afghan army and police being suspended.
With foreign combat troops withdrawing from the increasingly unpopular and expensive war, the enormous cultural divide still separating Afghans and their allies after 11 years of conflict has become more of a concern than ever.
The NATO-led coalition and its Afghan counterparts have created a special Joint Casualties Assessment Team to investigate every attack.
But in more than half of cases, attackers are either killed or escape and the motive never emerges, making it more difficult for the coalition to stem the surge.