Fifteen Guantanamo Bay inmates have been transferred, bringing the population of the detention center to 61 men, the Pentagon announced Monday night.

The 15 detainees, who were transferred to the United Arab Emirates, were part of the group of two dozen cleared detainees expected to be released this summer.

Six of the 15 were unanimously cleared for transfer. The other nine were cleared by a consensus of the six departments and agencies that make up the Periodic Review Board.

So far, 46 detainees have been transferred to other countries in 2016, including another large transfer of 10 detainees to Oman earlier this year, according to data maintained by the New York Times.

The transfers are part of President Obama's efforts to close the detention center before leaving office, a promise he made while on the campaign trail during his first run for president.

Rep. Ed Royce, R-Calif., and chairman of the House Foreign Affairs Committee, slammed the transfers as detrimental to U.S. security.

"In its race to close Gitmo, the Obama administration is doubling down on policies that put American lives at risk. Once again, hardened terrorists are being released to foreign countries where they will be a threat," Royce said. "Too many have already died at the hands of former detainees. I fear we will be dealing with the consequences of this recklessness for years to come."

The White House sent Congress a plan earlier this year that would see many cleared prisoners transferred to other countries under security agreements. Those who could not be transferred would be brought to a facility in the United States. The report specifically looked at moving them to a supermax prison in Colorado, the U.S. Navy brig in Charleston, S.C., and Fort Leavenworth, Ky.

But the plan was essentially dead on arrival in the Republican-controlled Congress and never gained traction, with many in those states arguing against having terrorists in their backyards. Lawmakers also criticized the plan for lacking details, such as the cost of picking a specific site for the suspected terrorists to be housed.

The high number of recent transfers appears to be Obama's attempt to sidestep the fight over moving prisoners to the U.S. by transferring as many as possible.

Sen. Kelly Ayotte, R-N.H., released an unclassified report last week detailing the terrorist affiliations of the 107 Gitmo detainees who were there as of Nov. 25, 2015, many of whom have been released.

"The more Americans understand about the terrorist activities and affiliations of these detainees, the more they will oppose the administration's terribly misguided plans to release them," Ayotte said in a statement. "The preeminent responsibility of the federal government is to keep the American people safe, yet the Obama administration's misguided commitment to releasing detainees in order to eventually close Guantanamo unacceptably gambles with our nation's safety."

Both the House and Senate National Defense Authorization Act for fiscal 2017, which is in the conference process, extends prohibitions on transferring Gitmo detainees to the U.S. Obama has threatened to veto the bill if the bans make it into the final version.

The Senate version of the bill would allow detainees to come to the U.S. for medical care, which can be costly to provide at the island prison, but previous efforts to pass this loosening of restrictions has been stripped out in conference with the House.

The detainees whose transfer was announced on Thursday are: Abd al-Muhsin Abd al-Rab Salih al-Busi, Abd al-Rahman Sulayman, Mohammed Nasir Yahi Khussrof Kazaz, Abdul Muhammad Ahmad Nassar al-Muhajari, Muhammad Ahmad Said al-Adahi, Abdel Qadir al-Mudafari, Mahmud Abd Al Aziz al-Mujahid, Saeed Ahmed Mohammed Abdullah Sarem Jarabh, Mohammed Kamin, Zahar Omar Hamis bin Hamdoun, Hamid al-Razak (aka Haji Hamidullah), Majid Mahmud Abdu Ahmed, Ayub Murshid Ali Salih, Obaidullah, and Bashir Nasir Ali al-Marwalah.