Three American soldiers are dead after being gunned down by an Afghan soldier in Nangarhar province.
The Taliban has claimed responsibility, saying the shooter was an infiltrator.
A fourth US soldier has been injured.
The so-called 'green-on-blue' insider attacks on American troops were a major problem several years ago.
Nangarhar province was also the site of the United States' 'mother of all bombs' attack in April.
Newshub.
