There was yet another green-on-blue attack in Afghanistan on Sunday in which two Americans and three Afghans were killed. The death of a U.S. soldier brings the total number of troop deaths in the Afghan war to over 2,000. 

Reuters reports a firefight broke out when a member of the Afghan National Army shot at American troops while they were going through a routine checkpoint. U.S. officials confirmed to the Associated Press a U.S. soldier was killed in the ensuring battle, bringing the death toll to 2,000. "Initial reports indicate that a misunderstanding happened between Afghan army soldiers and American soldiers," an Afghan government spokesman told the AP. One other American was killed in the ensuing gunfire. An Afghan official told the AP three Afghan soldiers were killed. 

There's a growing trend of 'insider attacks' in Afghanistan, and it's putting a significant strain on the relations between the two countries. Joint operations between Afghan security forces and U.S. troops were halted two week after one of the worst U.S. airpower losses in fifty years marked a bad string of insider attacks. A spokesman for the NATO troops stationed in Afghanistan told Reuters it was too early to tell what kind of effect this would have on joint operations resuming.