"The second time they brought me in for interrogation, they started questioning me and electrocuting me. I passed out for about five minutes. When I came to, I found myself in the cell, but my uncle wasn't with me. He might have been in interrogation. The third time they took me in for questioning, the last time, they pulled out my nails, they had pliers, or something like a screwdriver that they used."
Human Rights Watch has called on the UN to take action and refer the crimes and those indentified in the report to the International Criminal Court.
Amateur video appears to show a Syrian government tank positioned amid wreckage in preparation to open fire on the city of Douma.
Reuters is unable to independently verify the content of the videos, which were obtained from a social media website.
At a meeting in Geneva over the weekend, international powers agreed that a transitional government should be set up in Syria, but left open the question of whether president Assad might play a role in that process.
