The US military has ordered an investigation into claims of prisoner abuse at the Guantanamo Bay base in Cuba where terror suspects captured in Afghanistan are being held.
The Pentagon statement followed the release by a US civil liberties group of documents showing fresh claims of abuse of prisoners, including memos from the FBI.
In one of the documents, an FBI agent describes interrogations in which detainees were shackled hand and foot in a foetal position on the floor for as long as 24 hours.
The American Civil Liberties Union obtained the documents through the US Freedom of Information Act, often after filing lawsuits against the federal government for failing to comply.