(NBC NEWS) Most joint U.S.-Afghan military operations have been suspended following what authorities believe was an insider attack Sunday that left four American soldiers dead, officials told NBC News.

“We’re to the point now where we can’t trust these people,” a senior military official said. So far this year, 51 NATO troops have been killed in these so-called blue-on-green attacks. Sunday’s attack came a day after two British soldiers were shot dead by an Afghan policeman, Reuters reported.

“It’s had a major impact on our ability to conduct combat operations with them, and we’re going to have to back off to a certain degree,” the official said.

  • Text smaller
  • Text bigger
Note: Read our discussion guidelines before commenting.