The United States has transferred nine Yemeni men to Saudi Arabia from the US military prison at Guantanamo, including an inmate who had been on a hunger strike since 2007, US officials said.

The transfer marked the largest group of prisoners shipped out of the naval base in Cuba since President Barack Obama rolled out his plan to shut the controversial detention centre there before he leaves office.

"The United States is grateful to the government of the Kingdom of Saudi Arabia for its humanitarian gesture and willingness to support ongoing US efforts to close the Guantanamo Bay detention facility," the Pentagon said in a statement on Saturday.

The Saudis agreed, after lengthy negotiations, to take the nine Yemenis for resettlement and put them through a government-run rehabilitation programme that seeks to reintegrate them into society.

They could not be sent back to their homeland because US officials fear that the instability there would enable them to resume the "militant activities" that landed them at Guantanamo in the first place.

The most prominent of the transfers was Tariq Ba Odah, a 37-year-old Yemeni whom the military had been force-feeding daily since he went on a hunger strike in 2007. His legal team said he was down to 34kg, losing about half of his body weight.

Ba Odah's lawyer, Omar Farah, said the US government had "played Russian roulette" with his client's life and that his transfer "ends one of the most appalling chapters in Guantanamo's sordid history".

With the latest departures, there are now 80 prisoners at Guantanamo, most held without charge or trial for more than a decade, drawing international condemnation.

The transfers took place as Obama prepared to visit Saudi Arabia on Wednesday and Thursday for a summit with the Gulf Cooperation Council.

Source: Agencies