The Syrian government has carried out a state policy of extermination against thousands of detainees, UN human rights investigators say.
They accuse President Bashar al-Assad's regime of crimes against humanity, in a report for the UN Human Rights Council.
The study says both loyalist and anti-government forces have committed possible war crimes.
Many detainees were tortured, some were beaten to death, and others died from lack of food, water, or medical care.
The findings come from interviews with hundreds of witnesses and cover the period since the start of anti-government protests in March 2011.