WASHINGTON — A hunger strike by detainees who have been held for years without trial at the military prison at Guantanamo Bay, Cuba, has grown to involve at least 25 prisoners, the Defense Department disclosed on Wednesday.

That number includes eight who are being force-fed a nutritional supplement through a hose snaked into their nose while they are restrained in a chair.

There have long been about half a dozen prisoners at Guantanamo who refuse to eat and have been kept alive by force-feeding. But the number refusing meals among the 166-inmate population has recently surged.

According to the military’s count, as of March 15 there were 14 officially recognized hunger strikers. That number swelled to 21 by Monday and 24 by Tuesday, and is now at 25, said Captain Robert Durand, a spokesman for the prison. Two have been hospitalized for dehydration, he added.


Lawyers representing some of the detainees in habeas corpus lawsuits, who communicate with them during visits to the island and by phone, said that the number is significantly higher than the official count. The military said it is using criteria developed by the civilian Bureau of Prisons, which generally counts a prisoner who refuses nine straight meals as a hunger striker.

The origins of the hunger strike are disputed. David H. Remes, a lawyer for several Yemeni detainees who were cleared for repatriation years ago but remain imprisoned because of poor security conditions in Yemen, said he was recently told by clients that prison officials had started searching Korans, which inmates considered to be religious desecration, in a way they had not done since 2006.

A group of lawyers representing detainees, including Remes, sent letters on March 4 and March 14 to military officials raising alarm about the strike and asking for attention to alleviate its underlying causes, citing the purported Koran searches and a wider set of ‘‘regressive practices at the prison taking place in recent months, which our clients have described as a return to an older regime at Guantanamo that was widely identified with the mistreatment of detainees.’’


Durand, however, said that there had been no change to longstanding procedures for searching the Korans, in which prison translators, who are Muslims, touch the book. In a lengthy statement, he argued that the detainees were coordinating to ‘‘fabricate’’ claims of personal or Koran abuse as a tactic for garnering news media attention.

In phone interviews, Remes and Durand largely agreed, however, that a significant underlying condition for the recent unrest was the collapse of hopes that the US government would at some point let them go.

‘‘I think there was great hope that there would be fresh movement, and there was at the beginning’’ of the Obama administration four years ago, Durand said. ‘‘But the movement in the last year is not encouraging. I don’t dispute that there is frustration over that.’’

In 2009, President Obama inherited about 240 detainees from the Bush administration and ordered that the prison be closed by the end of his first year in office. He also established a task force to review each prisoner’s case; about half of the remaining inmates were ultimately approved for transfer.

But the effort to wind down the prison collapsed in the face of concerns over the security conditions in the countries where the bulk of the remaining low-level prisoners are from — most notably Yemen — and concerns in Congress about some former detainees who were linked to terrorist activities. Lawmakers have imposed an increasingly steep set of obstacles to additional transfers.


As a result, in 2012 only four prisoners were allowed to leave the island — two as a result of a military commission trial, and two who were ordered freed by a federal judge. A fifth prisoner, who had been repeatedly cleared for repatriation under both the Bush and Obama administrations and was ordered freed by a federal district court judge, only to have that order overturned by an appeals court, apparently committed suicide.