A member of the Afghan local police turned his weapon against two US occupation troops, killing them in a new “green-on-blue” attack.
The deaths on Friday take to 39 the number of international troops killed in 28 such attacks so far this year, according to NATO figures.
"Two US Forces-Afghanistan service members died this morning as a result of an insider threat attack in (western) Farah province," the US-led International Security Assistance Force said.
"A member of the Afghan Local Police turned his weapon against two USFOR-A service members. The attacker was shot and killed."
The attack came a week after six American troops were killed in a single day by local forces and will further erode trust between foreign troops and the Afghans they work with.
US Defense Secretary Leon Panetta said Tuesday he was "very concerned" about the rise in "insider attacks" and the impact they are having on cooperation with Afghan allies.