A Somali prisoner at Guantanamo Bay prison has told a military judge that he and others have been subjected to "mental torture" in the high-security section of the prison known as Camp 7.

Hassan Guleed testified at the war crimes tribunal in the Sept. 11 case that loud noises, vibrations and chemical smells have been used to pressure men there into cooperating with U.S. authorities.

Guleed was testifying Thursday on behalf of a Sept. 11 defendant who says the noises and vibrations disrupt his sleep and make it impossible for him to cooperate with his defense in the death penalty case. Military officials have denied that anything intentional has been done to the defendant.

The Somali prisoner is an alleged member of East Africa Al-Qaida, but has never been charged.