KABUL, Afghanistan, Aug. 29 (UPI) -- A gunman in an Afghan army uniform shot and killed three NATO soldiers in Afghanistan, NATO's International Security Assistance Force said.
The nationalities of the three were not immediately available.
CNN reported the attacker fired on NATO soldiers and killed three of them and that the incident was being investigated.
Separately, Australia's Department of Defense on its Web site Thursday said it could confirm "Australian Defense Force personnel have been killed in Afghanistan" but did not say how many died or other details, saying the department was in the process of informing their next of kin.
The recent rash of such insider attacks or what are called green-on-blue attacks, in which Taliban infiltrators or rouge Afghan soldiers attack coalition forces, has become a major concern for U.S. and NATO forces in Afghanistan. More than 40 coalition personnel have died in such attacks so far this year.
On Monday, another gunman reportedly killed two NATO troops before being killed by other NATO soldiers.
NATO commanders are stepping up efforts to ensure greater protection for their forces.
