A coalition of forces backed by the United States say Russian warplanes carried out an airstrike that injured several of their members.

According to a press release from the Combined Joint Task Force Operation Inherent Resolve — the U.S.’s campaign in Iraq and Syria against the Islamic State — Russian forces struck a target east of the Euphrates River in Syria near Dayr Az Zawr at around 12:30 a.m. local time Saturday.