Gunmen wearing Afghan military uniforms have killed two NATO soldiers at a base in the country's south, the coalition said, in the latest "insider attack" on foreign troops.Wednesday's attack in the volatile province of Helmand is the first such incident since April, highlighting long-simmering tensions between Afghan and foreign forces.
"Two Resolute Support service members died early this morning when two individuals wearing Afghan uniforms opened fire on their vehicle at an [Afghan security forces] compound in Helmand province," a NATO statement said.
"Resolute Support service members returned fire and killed the shooters," it added, without revealing the nationalities of the soldiers.
The Taliban did not immediately claim responsibility for the attack.
'Grudges and misunderstandings'
So-called "green-on-blue" attacks, when Afghan soldiers or police turn their guns on international troops, have been a major problem during NATO's long years fighting alongside Afghan forces.
Western officials say that most such attacks stem from personal grudges and cultural misunderstandings, rather than rebel plots.
The killings have bred fierce mistrust among local and foreign forces even as the rate of such incidents has dropped in recent years.
NATO ended its combat mission in Afghanistan in December last year, pulling out the bulk of its troops - although a 13,000-strong residual force remains for training and counterterrorism operations.
One of the worst insider attacks took place last August when US Major General Harold Greene was killed, the most senior American military officer to die in action overseas since the Vietnam War.