Russian airstrike 'kills scores of fleeing civilians' in Deir az-Zour
Children were among those killed as they tried to cross the river aboard rafts to escape areas where the Syrian regime is fighting the Islamic State group, the Syrian Observatory for Human Rights said.
Backed by Russian airstrikes, the forces of Syria's President Bashar Assad – notorious for their indiscriminate targeting of civilians – are pressing a battle to retake IS-controlled areas in the eastern province of Deir az-Zour.
A US-led international coalition has been providing air support to a Kurdish-Arab alliance also fighting the militants in its former northern bastion of Raqqa city and Deir az-Zour.
September was the deadliest month for Syrians this year, with the ongoing war killing at least 3,000 people including 955 civilians.
The Observatory relies on a network of sources inside Syria, and says it determines whose planes carry out raids according to type, location, flight patterns and munitions used.
The group has reported hundreds of civilians killed in operations against IS in Deir az-Zour and neighbouring Raqqa province, where the SDF is fighting with US support to capture the former IS bastion of Raqqa.
On Tuesday, the Observatory said a US-led coalition strike in Raqqa killed at least 18 civilians.
Russia has not acknowledged any civilian deaths in its strikes since it intervened in Syria's war in 2015, and dismisses the Observatory's reporting as biased.
The deaths in Deir az-Zour on Wednesday prompted outrage from the opposition Syrian National Coalition which described the incident as a "heinous crime".