A number of superstar musicians are demanding to know if their music was used to torture prisoners at the U.S. military detention facility in Guantanamo Bay, Cuba.

Photo taken on 01 June shows a guard and a Chinese Uighur Guantanamo detainee communicating at the Camp Iguana detention facility at Guantanamo Bay U.S. Naval Base, CubaMembers of Pearl Jam, R.E.M. and Trent Reznor of Nine Inch Nails are among the musicians who have endorsed a new campaign to declassify government documents on music-related abuses.

The effort is being organized by the newly launched National Campaign to Close Guantanamo, which claims prisoners at the facility were subjected to loud music as an interrogation tactic.

The group says it knows for certain the music of the band Rage Against the Machine was used to torture.

In a statement, the band's guitarist, Tom Morello, said "the fact that music I created was used in crimes against humanity sickens me."

President Barack Obama vowed to close Guantanamo by January, but senior officials say that goal is now unlikely, as logistical problems have prolonged the process.

More than 200 prisoners remain at the facility. A review team has been examining each detainee's case to determine who will be held for trial and who can be sent home or resettled in another country.

Some information for this report was provided by AP.