Islamic State (IS) militants have committed "mass atrocities" in Syria and have recruited children as fighters, the United Nations says.
In a report, investigators say public executions are a "common spectacle" in areas run by IS, one of the groups fighting against Syria's government.
The report also accuses the Syrian authorities of using chemical agents in eight separate incidents this year.
The conflict between government forces and several rebel groups began in 2011.
Some 200,000 people have died since then.
'Horrific torture'
The UN report details abuses by the Syrian government and several of the armed groups fighting it. The report says the Syrian air force has used barrel bombs on civilian neighbourhoods.
"In some instances, there is clear evidence that civilian gatherings were deliberately targeted" by government forces, the investigators said.
"In government prisons, detainees were subjected to horrific torture and sexual assault."
http://www.bbc.com/news/world-middle-east-28948555