Campaigners welcomed yesterday the release of another five inmates from Guantanamo Bay — but 122 more remain incarcerated at the notorious US concentration camp.

Four Yemeni citizens were transferred to Oman on Wednesday and one to Estonia.

None of the five had ever been charged with any crime but were held at the brutal prison for between 12 and 13 years and have been cleared for release for five.

Akmed Abdul Qadei, who was released to Estonia, has been behind bars since the age of 17. The others are Al-Khadr Abdallah Muhammad al-Yafi, Fadhel Hussein Saleh Hentif, Abd al-Rahman Abdullah Au Shabati and Mohammed Ahmed Salam.

President Barack Obama was elected on a pledge to close the camp, set up on a US-held naval base on Cuba by his predecessor George W Bush to hold “terror suspects” in legal limbo without access to the rights, such as a trial, they would be due on US soil.

“We are committed to closing the detention facility. That’s our goal,” US State Department spokesman Ian Moss said.

But progress on doing so has been slow, partly due to Congressional opposition.

Republicans in the Senate launched another bid this week to stop the government releasing anyone from the camp.

A Bill backed by Senator John McCain would repeal

­legislation allowing the US government to transfer prisoners.

Rightwingers have tried to use the murders at French magazine Charlie Hebdo as an excuse to keep Guantanamo’s inmates in prison, although there is no proof — and in many cases no suspicion — that those being transferred have had any connection with terrorism.

“Now is not the time to be emptying Guantanamo,” Senator Kelly Ayottee said. “This government continues to irresponsibly release detainees.”

Democrats hope that if Mr Obama releases enough prisoners Congress will conclude the camp is not economically viable.

West Virginia Democratic Senator Joe Manchin III tried to appeal to Republican hatred of public spending, saying it cost $3.3 million (£2.17m) a year to keep prisoners in the camp.