Three Afghan army soldiers opened fire on NATO troops in southern Afghanistan on Sunday, killing one and wounding six, a security officials said, dpa reported.
The shooting took place during a sports game at a joint military base in the southern province of Zabul. "One of the (Afghan) soliders was killed when coalition forces returned fire, but the other two fled," the official said.
The NATO-led military alliance confirmed one of its soldiers had died in a clash with Afghan army soldiers in Zabul, saying it had launched an investigation into the incident.
NATO troops have been training Afghan security forces ahead of a planned pullout. A classified document said in June attacks by Afghan troops on NATO soldiers were a "rapidly growing systemic threat" that could undermine the coalition's efforts to defeat the insurgency.
Taliban insurgents have often managed to infiltrate the ranks of the Afghan security forces. Attacks by Taliban infiltrators have caused more than five dozen NATO deaths since 2007.