Lawyers describe detainees' dramatic weight loss as guards attempt to end the protest through force-feeding and isolation

Lawyers representing hunger-striking detainees at America's controversial Guantánamo Bay prison have warned they fear some of the protesters could soon die in the ongoing protest.

The news comes as fresh details emerge about conditions at the camp from lawyers visiting clients, letters being written by inmates and phone calls from inside the prison.

They describe dramatic weight loss among many of the hunger strikers, force-feeding, putting protesters in isolation and at least one suicide attempt – though that has been denied by military authorities.

In a letter written by Djamel Ameziane – an Algerian prisoner who has been cleared for release after 11 years of being detained without trial – guards were accused of pressuring prisoners to break the strike. "They are trying to deprive us of everything they can," he wrote in the letter, extracts of which were seen by the Guardian. Ameziane added that inmates were being disturbed during prayers and that the temperature in cell blocks had been lowered to make inmates less comfortable.

Ameziane said that prisoners were being moved from the communal Camp 6 to the more isolated Camp 5 as a form of punishment for striking. "People who lose consciousness are taken to Camp 5 and some of them are put in isolation. Because of that, two days ago, one prisoner hung himself in his cell. They took him to hospital. I have not heard any news about him since," Ameziane wrote.

Earlier this week, a spokesman for the US military at the base, Capt Robert Durand, issued a statement in which he insisted there had been "no recent suicide attempts" at the prison. The military also denies it has mistreated any of the prisoners.

But lawyers and human rights advocates are painting a very different picture on what is going on at the prison than military officials. Lawyer Pardiss Kebriaei, who visited the isolated military base on Cuba last week, said that she met two of her clients who were both refusing food. One of them, Yemeni Ghaleb Al-Bihani, told her he had lost 40 pounds since joining the hunger strike which now involves a large majority of the base's prisoners and began some two months ago. Kebriaei said that Al-Bihani suffered from diabetes and was already on a "high risk" list of detainees who had previously diagnosed serious health problems.

"He seemed very weak," Kebriaei said. She added that another detainee she met, a second Yemeni called Sabry Mohammed, had lost some 30 pounds. Mohammed is one of the 86 detainees at the base who have been officially cleared for release. Kebriaie said that she was concerned that the length of the hunger strike, coupled with pre-existing health problems like the diabetes suffered by Al-Bihani, could result in deaths soon. "Death can occur. That is an objective medical fact," she said. "There are people in critical condition. Death is a distinct possibility."

Separately, British human rights lawyer Clive Stafford Smith, of the legal charity Reprieve, issued an affidavit describing a phone call from prisoner Younos Chekkouri. Smith said Chekkouri had lost about 30 pounds in weight. "Now it is just pain everywhere. I don't want to die in Guantánamo," Chekkouri told Smith, according to the legal document.

Chekkouri, who has also been cleared for release, has written signs on his cell window that read "Dial 911 – I am starving" and "SOS". He added: "Now 86 of us have been cleared for release and we are still here. Let us leave Guantánamo with clear hearts and without hatred. Hatred is evil and it harms the person who is hating as well as the person who is hated," Chekkouri said.

There is a fierce debate over the exact extent of the hunger strike and its causes. Advocates for the detainees say that the hunger strike now includes most of the men held in Camps 5 and 6 at the base representing around more than 100 of the camp's population of 166 prisoners. They say that the strike began over allegations of abuse of Qur'ans by guards. Omar Farah, who like Kebriaei works for the Centre for Constitutional Rights, said Ameziane had described a massive hunger strike involving almost everyone at the base. "The huge strike continues. There is mass participation," Farah said.

The military authorities, however, say that some 40 inmates are on hunger strike and that 11 of them are now being force-fed. In his statement Durand said that no prisoner was in medical danger. "No hunger striker is currently in medical danger, including those receiving enteral feeds. Enteral feeding is a nutritional intervention done before a patient is at risk of experiencing health consequences, and generally returns a patient to 100 percent ideal body weight in a short period of time," Durand said.

In recent testimony to Congress commanders from the base have said that the strikers are motivated by frustrations at their continued imprisonment and have denied that any abuse of the Qur'an has taken place. General John Kelly told a congressional committee in March that the Guantánamo prisoners were on "hunger strike light" and eating "a bit, but not a lot" as a way of protesting.

According to the Huffington Post, reporters recently requesting media visits to examine prison conditions at the camp have been refused until May 6 at the earliest. However, the protest has still succeeded in getting conditions at Guantánamo back into the headlines in the United States, though it appears that there is currently little political will to deal with the issue.

Though President Barack Obama vowed in his first year in office to close the base, it remains open with little prospect of release for anyone inside, including those cleared. Earlier this year, the State Department office meant to deal with resettling Guantánamo prisoners was closed down.

But on Thursday a group of human rights organisations, including the CCR and Amnesty International, sent a joint letter to Obama demanding the base be closed down and its inmates either released or given a trial in a civilian court. "We urge you to begin working to transfer the remaining detained men to their home countries or other countries for resettlement, or to charge them in a court that comports with fair trial standards. We also urge you to appoint an individual within your administration to lead the transfer effort," the letter said.

© Guardian News and Media 2013