A group of Guantanamo Bay detainees have become the first to be moved to a new maximum-security prison.
The new $37 million facility is designed to restrict contact among the prisoners and prevent attacks on guards.
US Navy commander Robert Durand said 42 detainees were taken to the new 178-cell prison in Cuba.
About 430 men are currently held at Guantanamo, including 100 who have been cleared for release and are awaiting transfer to another country.
UN human rights investigators and foreign governments have called on the US government to close the entire detention centre.
