An American-led airstrike Tuesday killed 18 Syrian fighters who were assisting in the fight against the Islamic State, The New York Times reports.
Coalition allies had requested Tuesday's strike, believing they had "identified ... an ISIS fighting position." It was in fact a "fighting position" of the Syrian Democratic Forces, who are assisting the U.S. in the fight against ISIS.
The United States Central Command called the strike "tragic" and said "the coalition's deepest condolences go out to the members of the S.D.F. and their families."
There have been two other instances in the past month where American-led airstrikes killed civilians or allies. The Pentagon is investigating airstrikes that killed dozens of civilians in a mosque in Syria and as many as 200 people in a building in Mosul, Iraq.