After the latest transfer, 198 detainees remain at the facility on the southern tip of Cuba.

Some of them will likely face trials in US criminal or military courts while others are
expected to be transferred abroad.

Yemen concerns

The US has been hesitant to transfer detainees to Yemen, as it suspects al-Qaeda elements are still active there and fears the country lacks the security resources to ensure that Guantanamo returnees will not join armed groups.

IN DEPTH

 

  US jail to hold Guantanamo inmates
  Yemen weighs rehabilitation issue
  Life after Guantanamo
  Guantanamo conditions 'deteriorate'
  Inside Guantanamo Bay

There have been months of high-level meetings between senior US and Yemeni government officials, including a visit to the capital Sanaa by Stephen Kappes, the deputy CIA director, The Washington Post reported on Friday.

Any former Guantanamo detainees arriving back in Yemen will not be immediately released, a Yemeni source in Washington said ahead of the transfer.

Yemen "never had a case where a prisoner was transferred and released immediately," the source told the AFP news agency.

"You have to go through a judiciary process, then a law enforcement process and then after that, that decides what happens."

The justice department said that since 2002, more than 560 detainees have departed Guantanamo for other destinations.

Barack Obama, the US president, acknowledged in November that he would
miss the self-imposed January deadline to close down Guantanamo.

US officials said on Tuesday that a number of Guantanamo detainees will be transferred to a maximum-security prison in the northern US state of Illinois.

Robert Gates, the defense secretary, has said the administration intends to release or extradite 116 Guantanamo detainees to either countries of origin or to third countries willing to accept them.