"We have received reports about a possible 'blue-on-green' incident in northeast Syria. The incident is under investigation and we will release more details at the appropriate time. The SDF [Syrian Democratic Forces] is a partner in the effort to defeat IS, and we will continue to support them as they liberate the last stronghold of ISIS in the Middle Euphrates River Valley," Operation Inherent Resolve spokesman Col. Sean Ryan told Sputnik.

The incident followed Syrian Arab News Agency reports about the coalition carrying out airstrikes in the province of Deir ez-Zor using white phosphorus, which is prohibited for use against civilians or in civilian areas under several Geneva Conventions.

The US-led coalition has been operating in Syria against terrorists since 2014 without receiving approval for its operations by either the UN or the Syrian government.

Reporter’s code: 50101