US troops in Afghanistan. PHOTO: REUTERS / File
"The wounded service members, who are in stable condition, are currently being treated," NATO's Resolute Support mission in Afghanistan said in a statement.
"The incident is under investigation." NATO did not release the identity of the American soldier killed or provide further details about the incident.
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The shooting happened at the airport in Tarinkot, the capital of Uruzgan province, a local police officer told AFP.
That information could not be immediately verified by Afghan or NATO officials.
The Taliban said on Twitter that "a patriot Afghan soldier opened fire on Americans in Uruzgan airport killing and wounding at least four American invaders".
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