Two members of the U.S. military were killed early Wednesday when a gunman wearing an Afghan military uniform opened fire on their vehicle at an Afghan military compound in Helmand province, Pentagon spokesman Capt. Jeff Davis said.
Officials with the U.S.-led NATO military coalition said other alliance soldiers returned fire, wounding the shooter as well as another individual also wearing an Afghan uniform.
Afghan and NATO officials are investigating the shooting. Officials did not identify the two Americans who were killed.
No group immediately claimed responsibility.
If the gunman is found to be a member of the Afghan security forces, the incident would be at least the third insider attack on foreign forces in Afghanistan this year. An Afghan soldier fatally shot three American contractors at Kabul airport in January; in April, an Afghan service member killed an U.S. soldier in the eastern city of Jalalabad.
The year 2012 saw the highest number of insider attacks against foreign forces. In recent years, the majority of such assaults have targeted Afghan soldiers and police.
NATO officials initially said that two gunmen had opened fire on the base in the southern province of Helmand, not one, and that both were killed by North Atlantic Treaty Organization forces. The coalition later issued an updated report clarifying that two individuals in Afghan uniforms were wounded in the incident.
Latifi is a special correspondent. Times staff writer W.J. Hennigan in Washington contributed to this report.