One U.S. service member was killed and two others wounded in an "apparent insider attack" in southern Afghanistan, the NATO-led mission in Afghanistan said.

NATO's training and assistance mission in Afghanistan, Resolute Support, said in a statement that the two U.S. service members injured in the July 7 incident were in stable condition and that an investigation was under way.

The statement did not provide further details, saying that the name of the U.S. service member killed in action would be withheld until notification of next of kin.

U.S. Lieutenant Colonel Martin O'Donnell, a spokesman for the NATO-led mission, declined to disclose the location of the incident or other details when reached by RFE/RL.

But AFP and The Washington Post cited unidentified Afghan officials as saying it happened in Uruzgan Province.

The Taliban said in a statement that a member of the Afghan security forces opened fire on U.S. troops in Uruzgan Province. The statement said that the attacker killed four people and injured several others.

O'Donnell told RFE/RL in an e-mail that the soldier killed in the July 7 incident was the third U.S. service member to have died in Afghanistan this year.

The incident comes just over a year after three U.S. soldiers were killed and one other was injured when an Afghan National Army soldier fired on a unit in Nangarhar Province.

Often referred to as "green-on-blue" attacks, insider attacks in which members of Afghan security forces -- or assailants dressed in Afghan uniforms -- fire on coalition troops have become less common in recent years.

O'Donnell told RFE/RL that the last insider attack in Afghanistan occurred in August 2017, leaving a Romanian soldier injured.

Around 14,000 U.S. troops are currently stationed in Afghanistan as part of the NATO-led mission, while also carrying out counterterrorism operations targeting Islamic State (IS) militants and Al-Qaeda.

With reporting by RFE/RL's Carl Schreck, Reuters, AFP, dpa, and The Washington Post