More than 17,000 people have died in detention in Syria since an uprising against President Bashar Assad's regime began in March 2011. That's according to a newly published report from Amnesty International citing horrific conditions in Syrian government detention centers.

The detention facilities operated by Syria's state security branches have long been criticized as black holes, where captives are cut off to the world without communication or lawyers. Amnesty researchers say that despite repeated requests, Syria has not allowed visits by international monitors.

So as part of the report, titled "It breaks the human," Amnesty has created a digital model of one of Syria's most notorious prisons — offering a glimpse into a prison network where the group says tens of thousands of people have disappeared.

Amnesty partnered with a forensic architecture team to build an interactive model of the Saydnaya prison outside Damascus. Researchers used testimony from hundreds of survivors to replicate the sights and sounds of Saydnaya. A video takes the viewer into a re-creation of the sprawling facility and the brutal detainee experience, from the initial "welcoming party" beatings to the daily battle for survival where an estimated 300 people are dying each month.

Former detainees reported cramped conditions in which more than 50 people might be crammed into cells of only 3 square meters. Prison authorities would routinely deny them food, water and basic medical treatment, creating a deadly environment where the detainees said even the most mundane of bruises or an ingrown nail could turn into a life-threatening infection.

Amnesty's findings back up previous reports on Syrian jails.

In February, the the U.N. Commission of Inquiry on Syria published an extensive report on conditions faced by detainees, including at facilities run by armed opposition factions as well as by the government. But the bulk of that report is dedicated to prisons run by state intelligence agencies, alleged to have committed the most systematic crimes against detainees. It accused Syrian authorities of carrying out a policy of extermination against detainees and demanded access to the prisons. The request was never granted.

Amnesty Syria researcher Nicolette Boehland tells NPR that the rights group is seeking to ramp up pressure on the U.S. and especially Russia — a Syrian ally — to allow monitors into these long-shielded facilities.

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