The attack Saturday in eastern Afghanistan also killed or wounded Afghan soldiers, the NATO alliance said in a statement. It did not provide further details, including the nationalities. The international coalition typically waits for national authorities to announce their own dead.
An Afghan military spokesman declined to comment.
Afghan soldiers and policemen—or militants in their uniforms—have gunned down more than 50 foreign troops so far this year, eroding the trust between coalition forces and their Afghan partners. An equal number of Afghan policemen and soldiers also died in these attacks, giving them reason as well to be suspicious of possible infiltrators within their ranks.
The attacks are taking a toll on the partnership between international and Afghan forces, prompting the U.S. military to restrict operations with small-sized Afghan units earlier this month.
The close contact—with coalition forces working side by side with Afghan troops as advisers, mentors and trainers—is a key part of the U.S. strategy for putting the Afghans in the lead as the U.S. and other nations prepare to pull out their last combat troops at the end of 2014, just 27 months away.