As many as 200 prisoners - more than a third of the camp - have refused food in recent weeks to protest conditions and prolonged confinement without trial, according to the accounts of lawyers who represent them. While military officials put the number of those participating at 105, they acknowledge that 20 of them, whose health and survival are being threatened, are being kept at the camp's hospital and fed through nasal tubes and sometimes given fluids intravenously.

The military authorities were so concerned about ending a previous strike this summer that they allowed the establishment of a six-member prisoners' grievance committee, lawyers said. The committee, a sharp departure from past practice in which the camp authorities refused to cede any control or role to the detainees, was quickly dissolved, the lawyers say.

Major Jeffrey Weir, a spokesman at the base, said that the prisoners who were being fed at the hospital were generally not strapped to their beds and gurneys but were in handcuffs and leg restraints. A 21st prisoner at the hospital is voluntarily accepting liquid food.

Weir said the prisoners usually accept the nasal tubes passively because they know they will be restrained and fed forcibly if necessary. "We will not let them starve themselves to the point of causing harm to themselves," he said, describing the process as "assisted feeding" rather than force-feeding. On at least one occasion, he said, a prisoner was restrained and forcibly fed.

One law enforcement official who has been fully briefed on the events at Guantánamo said senior military officials had grown increasingly worried about their capability to control the situation.

A senior military official, also speaking on the condition of anonymity, described the situation as greatly troublesome for the camp's authorities and said they had tried several ways to end the hunger strike, without success.

The comments of the officials who spoke on the condition of anonymity, probably because their accounts conflict with the more positive descriptions in official military accounts, generally mirrored the statements of lawyers for the detainees, who have received their information from face-to-face interviews with their clients.

Clive Stafford Smith, a British lawyer for several of the detainees, said he had been visiting some of his clients in August when the most recent strike began. He said that a detainee, Omar Deghayes, told him that the strike was largely to protest their long imprisonment without being charged with any crime as well as the conditions of their confinement.

He said that Deghayes, a Libyan who has lived in London, told him: "Look, I'm dying a slow death in this place as it is. I don't have any hope of fair treatment, so what have I got to lose?"

Stafford Smith said an earlier hunger strike ended on July 28 after the authorities agreed to improve conditions.

He said that one inmate, Shaker Aamer, negotiated the end to that hunger strike with a camp official he identified as Colonel Michael Bumgarner, who said he had been authorized to address some of the prisoners' grievances. Stafford Smith, who represents Aamer, said his client told him that Bumgarner said he would ensure that the detainees would thereafter be treated "in accordance with the Geneva accords." That included, Stafford Smith said, the establishment of the six-member committee to represent the prisoners in talks with the authorities. Such representative committees are called for in the Geneva conventions, although they had not been formed at Guantánamo.

The Bush administration has said that while the Guantánamo detainees are not entitled to the protections of the Geneva conventions, they are generally treated by its standards.

Stafford Smith said the committee functioned for only a few days before the authorities disbanded it.

Weir disputed Stafford Smith's description of a prisoners' grievance committee. "There have been no meetings with detainees refusing to eat," he said in a written statement in response to a question about the existence of such a committee. He said that commanders and soldiers interact with the prisoners daily and that they are also made aware of prisoners' needs and complaints from representatives of the International Committee of the Red Cross. He declined to elaborate further.

Stafford Smith said the current strike began after some detainees reported witnessing the abuse of a prisoner, Hisham Sliti, when he returned to his cell after an interrogation session.