Two men in Afghan military uniforms on early Wednesday opened fire on a NATO vehicle in south province of Helmand, killing two soldiers in the latest insider attack on foreign troops in the country, said a NATO coalition spokesman.
Soldiers whose nationalities are unknown returned fire killing the attackers, according to the spokesman.
'Green on blue' attacks, the phrase used to describe assaults on foreign troops by Afghan soldiers or police are a major ongoing problem for the NATO mission in the country.
The incident that took place in Helmand is the first 'insider attack' since April, which highlighted the long lasting tensions between Afghan and foreign forces.
A NATO statement said, "Two Resolute Support (NATO) service members died early this morning when two individuals wearing Afghan military uniforms opened fire on their vehicle at an Afghan security forces compound in Helmand Province."
"Resolute Support service members returned fire and killed the shooters," it added.
No one immediately claimed responsibility for the attack. Western officials explained the reasoning behind the assault as personal grudges and cultural misinterpretations rather than riot plots.
In December, NATO’s combat mission formally ended, however a small foreign force of about 12,500 mainly US troops has stayed in the country to train the local security forces.
NATO troops have adopted special security measures in recent years to try to counter any threats.
Since the fall of the Taliban regime in 2001, the Afghan Military and NATO troops have been struggling with insider attack killings, high casualty rates and mass desertions.
Following the announcement of the death of longtime leader Mullah Omar amid a bitter leadership dispute, the Taliban are stepping up their summer offensive, launched in late April.
After Omar’s death announcement, his longtime trusted deputy Mullah Akhtar Mansour was named as the new Taliban chief in late July.