Tens of thousands of civilians are still missing after being detained arbitrarily during 10 years of civil war in Syria, UN investigators say.
Thousands more have been tortured or killed in custody, according to a new report detailing alleged war crimes and crimes against humanity by all parties.
Victims and witnesses described “unimaginable suffering”, including the rape of girls and boys as young as 11.
The issue is a “national trauma” that must be addressed, the report says.
Syria has been devastated by a conflict that erupted after President Bashar al-Assad’s government responded with deadly force to peaceful anti-government protests in March 2011.
The fighting has left at least 380,000 people dead and caused half the population to flee their homes, including almost six million refugees abroad.
The report by the UN Human Rights Council’s Independent International Commission of Inquiry on Syria was based on more than 2,650 interviews and investigations into more than 100 detention facilities. It documents violations by almost every major party to the war that were apparently intended to intimidate and punish perceived opponents.
“The government forces’ arbitrary detention of political opponents, journalists, human rights activists and demonstrators were both a root cause and a trigger of the conflict,” the commission’s chairman, Paulo Pinheiro, said.
“Armed groups and UN-designated terrorist organizations such as [Hayat Tahrir al-Sham] and [the Islamic State group] then also started depriving people of their liberty, committing heinous violations against them, often with sectarian undertones.”
Former detainees described not seeing daylight for months, being forced to drink unclean water and eat mouldy food, sharing overcrowded cells without a toilet with hundreds of other people, and being denied medical care.
Those who were allegedly tortured or subjected to inhuman treatment in government-run prisons told investigators of at least 20 different methods used by security personnel to extract false confessions.
These included administering electric shocks, the burning of body parts, pulling off nails and teeth, and hanging people from one or two limbs for prolonged periods.
“They tortured me…, then the interrogator told me: ‘We can kill you here and now, nobody will ever know’,” recalled a man held by the government in Homs.