(NBC NEWS) An apparent insider attack by Afghan forces has killed a U.S. service member and a contractor, officials said Sunday – bringing the total number of U.S. troops killed inside Afghanistan to 2,000 according to some measures.

A U.S. official confirmed the latest death in the 11-year-old conflict on Sunday.

The American service member killed was a soldier. The American contractor was working as a trainer for either the Afghan army or police, according to NBC News.

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