Two US soldiers were killed and six wounded in an attack in eastern Afghanistan’s Nangarhar province when an Afghan dressed in an Afghan army uniform opened fire.
Afghanistan’s defence ministry said one Afghan soldier was also killed and three injured in the assault.
A member of Nangarhar’s provincial council, Ajmal Omer, said the gunman was killed.
The US Department of Defense has named the dead American soldiers as Sergeant Javier Jaguar Gutierrez, 28 and Sergeant Antonio Rey Rodriguez, 28.
In a statement, the US military said an individual in an Afghan uniform opened fire on the combined US and Afghan force with a machine gun.
"We are still collecting information and the cause or motive behind the attack is unknown at this time," it read.
An Afghan defence ministry official appears to have confirmed the gunman was an Afghan soldier, saying he had argued with the American troops before opening fire.
He was not a Taliban infiltrator, the official said.
There have been numerous attacks by Afghan national army soldiers on their allied partners during 18 years of America’s protracted war in Afghanistan.
Six US service members have been killed in Afghanistan since the start of 2020, including Saturday’s casualties.
Last year, 22 US service personnel died in combat there.
Cover image: A US flag flying over a mission support site in Nangarhar province, Afghanistan (Picture: US Air Force).