U.S. Defense Secretary Donald Rumsfeld travels to Cuba Sunday to visit the U.S. Navy Base at Guantanamo Bay, where 158 Taleban and al-Qaida detainees are being held.

Mr. Rumsfeld will get a first-hand look at the detention center known as Camp X-Ray, where 158 Taleban and al-Qaida prisoners from Afghanistan are being held.

The United States began flying the detainees to Guantanamo Bay two weeks ago, but has temporarily suspended further transfers until more facilities are built.

The suspension came amid criticism from some human rights groups and foreign politicians over the treatment of the detainees and for the U.S. refusal to designate them as official prisoners of war.

But Mr. Rumsfeld says they are being treated humanely and in accordance with international conventions. He says controversial restraints and blindfolds have been used while the prisoners are moved, because they are extremely dangerous.

At Camp X-Ray, the detainees, who are believed to come from 25 countries, are held in individual cells with concrete floors, wooden roofs and chain-link fence walls. They receive regular meals, showers, exercise and medical treatment, if needed. The Navy has provided them with religious materials, as well as a Muslim cleric, one of only a few in the U.S. military.

U.S. officials began questioning the detainees last Wednesday in an effort to uncover details of terrorist activities in Afghanistan and worldwide. Some may eventually be held for trial by a special military tribunal, but others are expected to be returned to their home countries.

The U.S. base at Guantanamo Bay is the oldest American military facility on foreign soil. It was originally leased in 1903 as a fueling station. Now, some 3,000 military personnel, civilians and family members live on the base.