There were "errors in the development of intelligence, as well as missed opportunities for coalition members on duty to recognise and voice contrary evidence to decision-makers," the US military's Central Command said in a statement following a six-week probe into the September 17 attack near Deir Azzor.
Australian, Danish, British and American planes all took part in the air strike, which the Syrian Observatory for Human Rights monitoring group has said killed at least 90 regime troops.