An Afghan soldier has opened fire on a group of US troops at a military camp in the southern province of Helmand, wounding at least three of them, officials say.
A spokesman for US forces in Afghanistan confirmed that the attack took place at Camp Antonik in Washer district on Sunday evening.
"Three US soldiers were wounded this afternoon when an Afghan soldier opened fire on them at a base in Helmand province. Coalition security forces on the base killed the soldier to end the attack," media outlets quoted the spokesman as saying.
"The US soldiers are receiving medical treatment at this time and we will release more information when available."
Omar Zwak, the provincial governor's spokesman, said an Afghan soldier was also killed in the shootout.
The assault, which highlights long-simmering tensions between Afghan and foreign forces, is the first "insider attack" on US-led forces this year.
The so-called insider attacks, when Afghan soldiers and police turn their guns on their colleagues or on US-led troops, have created mistrust between local forces and their US-led partners during the more than 15 years of war.
In May last year, gunmen wearing Afghan military uniforms shot dead two Romanian troops in neighboring Kandahar province.
According to Western officials, most such assaults stem from personal grudges and cultural misunderstandings rather than militant plots.
Currently 8,400 US troops are stationed in different bases in Afghanistan. US General Joseph Votel, who is in charge of military operations in the Middle East, has asked for even more troops to be deployed to Afghanistan.
The Pentagon has said it would deploy some 300 US Marines to Helmand this spring to assist a NATO-led mission to train Afghan forces. The American forces had engaged in heated combat across the poppy-growing province until they pulled out in 2014.
US drone attacks kill 12 in eastern Afghanistan
In a separate development, Afghan officials confirmed on Sunday that at least a dozen militants including two of their commanders were killed in separate CIA-operated drone attacks on Saturday.
Mohammad Rahman Ayaz, a spokesman for the provincial governor in the eastern province of Paktika, said the two militant commanders were targeted by a drone while they were traveling in a vehicle in Barmal district on Saturday.
At least 10 other militants were killed in separate airstrikes in Paktika. Zelmai Wesaa, the provincial governor for Paktika, said the attack took place in Dand-e Patan district near the Pakistani border.
The CIA spy agency has used hundreds of unmanned aircraft to conduct surveillance flights and airstrikes since Washington and its allies invaded Afghanistan in 2001. The CIA regularly uses drones for airstrikes and spying missions in Afghanistan as well as Pakistan’s northwestern tribal belt near the Afghan border.