A dozen former detainees at Guantanamo Bay are suspected of returning to the battlefield on behalf of various militant groups, according to a report released by the Obama administration Monday.

The Office of the Director of National Intelligence (ODNI) said that seven of the 144 detainees who have been freed since President Barack Obama took office in 2009 have been confirmed to have returned to fighting as of Jan. 15. The ODNI's previous report, from this past July, said six detainees had gone back to battle.

The number of suspected recidivist detainees was double the number in this past July's report. The increase is likely to spark new protests by Republicans opposed to President Obama's plan to shut down the facility and transfer dozens of detainees to prisons in the U.S.

Under Obama's plan, roughly 35 of the 91 current prisoners will be transferred to other countries in the coming months, leaving up to 60 detainees who are either facing trial by military commission or have been determined to be too dangerous to release but are not facing charges. Those detainees would be relocated to a U.S. facility.

House Speaker Paul Ryan, R-Wis., said last month that Republicans are taking legal steps to stop Obama from closing the prison. Ryan told reporters that lawmakers have the votes to block Obama's plan in Congress and enough votes to override any veto.

"These detainees cannot come to American soil," Ryan said at the time.

The ODNI report does not specify where or for which groups the former detainees are confirmed or suspected to be fighting.

The report also found that 111 of 532 prisoners released by the George W. Bush administration had returned to the battlefield, while another 74 were suspected of doing so.

The Associated Press contributed to this report.

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