Cuba charged Friday that the U.S. base on the east end of the communist island had become a "concentration camp," deriding its use as a holding center for terrorism suspects.
"In the territory illegally occupied by the Guantanamo Naval Base, hundreds of foreign prisoners are subjected to indescribable humiliations," said a statement released Friday by Cuba's National Assembly.
Cuba has long opposed the presence of the American base, which operates in the eastern part of the island under a treaty signed long before the 1959 revolution that brought Fidel Castro to power.
But until Friday, Cuba had withheld criticism and even offered the first prisoners medical assistance when they arrived two years ago.
The statement said the prisoners are "totally isolated, without the possibility of communicating with their families or access to appropriate legal defense." It added that "some of the very few who have been freed have narrated the horrors of that concentration camp."
However, U.S. officials have repeatedly argued that the prisoners were being well treated.
"Should our servicemen and women be in the same position, I would hope they would be treated in the same humane manner," Maj. Gen. Geoffrey Miller, commander of the detention mission at Guantanamo, told The Associated Press in an interview earlier this year.
The U.S. government currently holds more than 600 men on the base, detained in Afghanistan and Pakistan and elsewhere on suspicion of terrorism.
Because they are being held on foreign land, the Bush administration has maintained the men have no rights to the American legal system.
Miller says that the prisoners are treated humanely under many of the principles of the Geneva Conventions. Because the U.S. government has classified the men as "enemy combatants" rather than prisoners of war, they are not entitled to the same protections under the conventions.