Four former Guantanamo Bay and Abu Ghraib prisoners have shined a light on some of their darkest days in a series of recent interviews reported by CNN and The Washington Post.

Mullah Abdul Salam Zaeef, a former prisoner who goes by the alias Abu Ahmed, a former detainee only identified as Amir and Lakhdar Boumediene described the harsh interrogation methods used against them.

Zaeef, a former associate of Taliban leader Mullah Omar, told CNN that U.S. officials beat him and put him into the snow at Bagram Air Base until he was unconscious. He was later transferred to Guantanamo Bay, and released in 2006 after more than three years in detention, CNN reported.

Ahmed, who served a 20 month detention beginning in 2003, told CNN that he was forced to live without clothes at Abu Ghraib for 32 days.

Amir, who was detained from 2003 to 2004 in Abu Ghraib, told CNN he had a collar put around him and forced to howl like a dog. Another time, he was sodomized with a broomstick, according to CNN.

Boumediene, who was recently released to France after seven years at Guantanamo Bay, was “roughly (lifted) from the chair where he was strapped, so the shackles dug into his flesh” during his interrogations, according to The Post.