Russian airstrikes have killed 69 civilians and injured dozens of others in the past three days in Deir ez-Zoor.
Activists said on September 12 the strikes hit civilian encampments at a river crossing on the western bank of the Euphrates as well as ferries in the river itself.
Reuters news agency reported that the Russian Defense Ministry did not immediately respond to requests for comment.
Civilian deaths have mounted as Russian-backed Assad terrorists and US-supported PKK-affiliated SDF press separate assaults against the extremist group ISIS in Deir ez-Zoor, the oil-rich area near the Iraqi border.
ISIS terrorists, who captured large swathes of Syrian territory in 2014, are opposed by all sides and are being driven from most of their strongholds.