NATO opens investigation into ‘green-on-blue’ attack which resulted in the first such killing in nearly a year.

A US soldier has been killed and two others wounded in an “apparent insider attack” in southern Afghanistan, according to NATO.

The so-called “green-on-blue” attack, in which Afghan forces fire on international troops with whom they are working, resulted in the first such killing in nearly a year.

“The wounded service members, who are in stable condition, are currently being treated,” NATO’s Resolute Support mission in Afghanistan said in a statement on Saturday.

“The incident is under investigation.”

NATO did not release the identity of the soldier killed or provide further details about the location of the incident.

A local police officer told AFP news agency that the shooting happened at the airport in Tarinkot, the capital of Uruzgan province.

On Twitter, the Taliban also gave Uruzgan as the location.

“A patriot Afghan soldier opened fire on Americans in Uruzgan airport killing and wounding at least four American invaders,” the group said.

Currently, there are about 14,000 US troops in Afghanistan, providing the main component of the NATO mission to support and train local forces there.

Some of the US forces are involved in counterterrorism operations, particularly against the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group.

The last “green-on-blue” attack occurred in August 2017 when a Romanian NATO soldier was killed.

Over a year ago, three US soldiers were killed by an Afghan soldier in the eastern province of Nangarhar.

The latest incident comes as Lieutenant-General Scott Miller is set to become the next commander of US and NATO forces in Afghanistan.

He will take over from General John Nicholson, who is rotating out of his post after a two-year deployment.

Miller’s deployment to Afghanistan, which would see him promoted to four-star general, comes at a time when local security forces are still struggling to contain a resurgent Taliban.

ISIL is also maintaining its eastern and northern footholds despite an intensified aerial bombing campaign by Afghan and US forces.

Afghan civilians increasingly found themselves in the crosshairs during an unusually intense period of fighting last winter.

A US Defence Department report released earlier this month found civilian casualties had increased 73 percent between December and May compared with the same period the year before.

The document also found a 14 percent increase in the number of Afghan army personnel killed or wounded while on local patrols and during checkpoint operations.