GENEVA - United Nations investigators accused Syria on Monday of carrying out a massive "extermination" of detainees from its civilian population, alleging that it amounts to "a crime against humanity."
The investigation, compiled by the Independent International Commission of Inquiry on Syria, is based on interviews with more than 600 survivors and witnesses of prison life in Syria.
Investigators accused the Syrian government, armed opposition and terrorist groups of war crimes and crimes against humanity, saying the large-scale killings of Syrian combatants and civilians, including children, in secret detention centers run by these groups, occur with impunity.
Thousands held, 'disappeared'
The report strongly suggests that the government of President Bashar al-Assad is holding tens of thousands of detainees at any one time and that thousands more have "disappeared" after their arrests or gone missing after being abducted by armed groups.
The U.N. report accused Damascus of starving the detainees or leaving them to die with untreated wounds and disease. It said Assad's government has "engaged in the multiple commissions of crimes, amounting to a systematic and widespread attack against a civilian population."
Paulo Sergio Pinheiro, chairman of the independent commission, said people in government detention centers are subjected to violations on a massive scale. He said they live in unsanitary and overcrowded cells with little food and no medical care.
He said thousands have been beaten to death or died as a result of torture.
“State officials are aware that prison conditions often result in the death of detainees. ... They deliberately try to conceal the fact that these ... deaths are caused by deliberate acts or omissions by high-level superiors," Pinheiro said.
The report covered the period from March 2011 to November 2015 -- the first 4½ years of the ongoing Syrian civil war.
However, no side comes out untarnished in this conflict, which has claimed more than 250,000 lives. The report said anti-government armed groups and terrorists also hold prisoners under brutal conditions.
The report found the terrorist group Jabhat al-Nusra and some rebel organizations have committed war crimes of murder, cruel treatment and torture. It also accused the Islamic State group of subjecting detainees to serious abuses, including torture and summary execution, amounting to crimes against humanity and war crimes.
The U.N. investigators said they believed that "high-ranking officers" and other government officials knew of the deaths and of bodies being buried in mass graves.
The special inquiry into the Syrian treatment of its civilian population called for the U.N. Security Council to impose "targeted sanctions" against Syrian civilian and military officials complicit in the deaths and torture, but did not name them.
The investigators called for referral of the cases against the suspected war criminals to prosecutors at the International Criminal Court at The Hague in the Netherlands. Their names are being kept in a U.N. safe in Geneva.