The U.S. has transferred 11 Yemeni men to Oman after holding them for more than two decades without charge at the U.S. naval base in Guantanamo Bay, Cuba.

The transfer announced Monday leaves six never-charged men still being held at Guantánamo, two convicted and sentenced inmates, and seven others charged with the 2001 attacks, the 2000 bombing of the USS Cole, and 2002 bombings in Bali, Indonesia.

The United States sent 11 Yemeni detainees at the Guantanamo Bay detention facility to Oman, the Pentagon said on Monday, leaving just 15 people at the infamous detention centre.