Tensions between detainees and the U.S. military at Guantánamo Bay, Cuba, have spiked in recent weeks, with a hunger strike at one of the camps reflecting growing despair the Obama administration has abandoned efforts to repatriate prisoners cleared for release, according to defense lawyers and other people with access to information about detention operations.

Most of the 166 detainees remaining at Guantánamo Bay are housed in Camp 6, a facility that until recently held men the military deemed “compliant.” But the camp, where cell doors are left open so detainees can live communally, has been at the center of a series of escalating protests since January.

The lawyers and human-rights advocates said there is a mass hunger strike at Camp 6 that is threatening the health and lives of a number of detainees. In a letter to Defense Secretary Chuck Hagel, they said they have received “alarming reports” of men losing “over 20 and 30 pounds” and that “at least two dozen men have lost consciousness due to low blood glucose levels.”

A military official said Friday that 14 detainees are on hunger strikes and six are being force fed. Others have been refusing meals but eating nonperishable food stashed in their cells, officials said.

Navy Capt. Robert Durand, a prison spokesman, said “claims of a mass hunger strike ... are simply untrue.”

The International Committee of the Red Cross (ICRC), the only outside organization allowed unrestricted visits to the camps, said it visited Guantánamo from Feb. 18 to 23 and “is aware of the tensions at the detention facility.”

“The ICRC routinely follows the situation of detainees on hunger strikes and continues to do so today,” the group said in a statement. “The ICRC believes past and current tensions at Guantanamo to be the direct result of the uncertainty faced by detainees.”

The Red Cross officials at the ICRC would not comment on a report that a Red Cross employee was splashed with a mixture of feces and urine during the February visit. Durand said guards have been splashed with bodily fluids.

The immediate trigger for the protests was a series of searches in Camp 6 in which detainees said their Qurans were desecrated by guards who looked through them.

Pentagon spokesman Lt. Col. Todd Breasseale said no member of the guard force ever touches a Quran, and any examination of Qurans would be conducted by the facility’s cultural advisers, most of whom are Muslim. He also noted that detainees have used their Qurans to hide contraband.

Of the remaining detainees at Guantánamo, the administration has said, more than 80 are cleared for release if they can be returned to their home country or resettled in a third country. But Congress has imposed a series of restrictions, and transfers out of Guantánamohave ground to a halt.

In January, the administration closed the State Department office charged with negotiating the transfer of detainees and accelerating the closure of the facility.