Amnesty International says Russian air strikes in Syria may amount to war crimes after gathering reports on hundreds of civilians killed in their homes, medical facilities and other public spaces.
The UK-based human rights organisation said it conducted remote research on 25 attacks between September and November 2015, with at least 200 civilians killed.
Russia, which has entered Syria's four-year civil war on the side of its long-time ally, President Bashar al-Assad, denied its forces had targeted civilians in opposition-held areas, saying that they were focused on terrorist targets.
But Syrian residents and activists in areas held by the rebels fighting Mr Assad have for weeks been sending reports and videos of civilian targets that they claim were hit by Russia.
These have included strikes on an area where humanitarian aid convoys gather in Syria's northern border town of Azaz, as well as the bombing of a vegetable market in Ariha in northern Idlib province, which killed more than 35 people.