The US insists the detainees are enemy combatants
US authorities have dropped war crimes charges against five inmates held at the Guantanamo Bay detention centre.
The men were named as Noor Uthman Muhammed, Binyam Mohamed, Sufyiam Barhoumi, Ghassan Abdullah al-Sharbi and Jabran Said Bin al-Qahtani.
No reason has been given but a military spokesman said new charges could be filed against the suspects.
Last month, a prosecutor in charge of the cases resigned after criticising his own office's practices.
The US has confirmed the Cuba facility will not be closed before President George W Bush leaves office in January.
"The president and his administration are working to get to a position where Guantanamo could be closed - and have been for some time," said White House spokeswoman Dana Perino, confirming earlier media reports.
The Bush administration sees the Guantanamo Bay centre as a vital tool in the "war on terror".
But critics say it is a legal black hole in which suspects have been abused and face either military tribunals or open-ended imprisonment.
Last UK resident
The two contenders seeking to succeed Mr Bush, John McCain and Barack Obama, say they want to close the Guantanamo detention centre.
On Tuesday, the lawyer of Binyam Mohamed criticised the US government after all terror charges were dropped against his client.
"Far from being a victory for Mr Mohamed in his long-running struggle for justice, this is more of the same farce that is Guantanamo," Stafford Smith said.
"The military has informed us that they plan to charge him again within a month" after the US presidential election, Mr Smith said.
Mr Mohamed, 30, is the last UK resident held at Guantanamo Bay.
Last month, Army Lt Col Darrel Vandeveld - who had been appointed prosecutor for all five cases - resigned after accusing his own office of withholding information.
The Guantanamo Bay chief prosecutor has appointed new trial teams - to review evidence, co-ordinate with intelligence agencies and recommend what to do next, military spokesman Joseph DellaVedova said.