The United States has released 11 Yemeni detainees from the controversial naval base at Guantanamo Bay, Cuba, where they had been held for over two decades without charge.

The Pentagon said late on Monday that the 11 men had been transferred to Oman, as the Biden administration pushes to clear the facility of uncharged prisoners in its final weeks.

"The United States appreciates the willingness of the government of Oman and other partners to support ongoing US efforts focused on responsibly reducing the detainee population and ultimately closing the Guantanamo Bay facility," the Department of Defense said in a statement.

Among the men released in the latest transfer was Shaqawi al Hajj, who had carried out multiple hunger strikes in protest at his 21 years in prison without charge, preceded by two years of detention and torture, according to the US-based Center for Constitutional Rights.

The announcement came a week after the US said it had repatriated another detainee to Tunisia, reducing the total number of inmates being held at Guantanamo to 15.

More than 20 years of detention

The Guantanamo Bay facility was established under former President George Bush to house prisoners captured by the US during its "war on terror" in the wake of the attacks on September 11, 2001.

At its peak, the notorious detention center held around 700 mostly-Muslim men in reportedly brutal conditions, according to rights groups.

Outgoing President Joe Biden pledged to try to shut down Guantanamo prior to his election in 2020, but it remains open with just weeks left in his term.

Successive administrations have also tried and failed to finally close the facility, often citing difficulties in finding suitable countries willing to repatriate detainees.

Guantanamo's remaining detainees

Many of those stuck in Guantanamo are from Yemen, a country which is dominated by the Iran-allied Houthi militant group following decades of war.

Of the 15 remaining detainees, seven have been charged with war crimes in including involvement in the 9/11 attacks and two have been convicted and sentenced.

But six have still never been charged with any crime and are eligible for transfer for review.

mf/zc (AP, AFP, Reuters)