Military jailers are forcing Bradley Manning, the 23-year-old soldier accused of passing classified documents to, to strip naked in his cell at night and sleep without clothing, a requirement his lawyer says was imposed after Manning made a “sarcastic quip” about his confinement.

For most of the past eight months, Manning has been required to sleep wearing only boxer shorts, because of his status as a detainee under “prevention of injury watch,” said 1st Lt. Brian Villiard, a spokesman for the military detention facility, or “brig,” in Quantico. Beginning Wednesday night, the facility commander ordered that Manning turn over his boxers, too.

“The intention is not to cause any sort of humiliation or embarrassment,” Villiard said. “The intention is to ensure the safety and security of the detainee and make sure he is able to stand trial.”

Villiard said he could not explain how Manning might harm himself if he were allowed to keep his underwear, citing rules to protect detainees’ privacy. All he could say was that “circumstances warranted” the measure, which was ordered by the brig commander, Chief Warrant Officer 2 Denise Barnes. The requirement will remain in effect until a review next week, he said.

But Manning’s attorney, David E. Coombs, said he believed the order was “punitive” under the “guise of being concerned” about Manning’s welfare.

In a blog post Saturday, Coombs gave this account of how the boxers were taken away: On Wednesday, Manning was told he would continue to be kept under the restrictions of prevention of injury watch, that there was nothing he could do to change his maximum-custody status and that the brig commander considered him at risk of self-harm. Manning then said that the restrictions were “absurd” and that if he wanted to harm himself using an item of clothing, he could do so “with the elastic waistband of his underwear or with his flip-flops.”

Without consulting the facility’s mental health provider, the brig commander used Manning’s quip as “justification” to increase the restrictions on him, Coombs said. He said Manning was not placed under suicide watch because that would have required a mental health provider’s recommendation that the brig commander lacked.

In response to this specific incident, the brig psychiatrist assessed Manning as “low risk,” Coombs wrote. In particular, the psychiatrist said that Manning’s statement about his underwear waistband was “in no way prompted by ‘a psychiatric condition.’ ”

Villiard did not immediately respond to messages left late Saturday seeking comment on Coombs’s claim.

The conditions of Manning’s confinement have become controversial, with the United Nations special rapporteur on torture saying he submitted a formal inquiry to the State Department about Manning’s treatment. The State Department confirmed Saturday that U.S. officials “have met with the special rapporteur and are preparing a formal response.”

Under prevention of injury watch, Manning sleeps on a mattress with a built-in pillow. He has no sheet, only a blanket designed so that it cannot be shredded.

He is in maximum custody, which means he is allowed out of his cell for only one hour each day — to exercise by himself, indoors or outdoors. The maximum-custody designation is based on the seriousness of the alleged offense and the potential length of the sentence, as well as the military’s duty to protect him from himself and others, Pentagon spokesman Geoff Morrell said last month.

Morrell said he had visited Quantico to observe the conditions of Manning’s detention. “I came away enormously impressed by the professionalism of the brig staff and reassured that the manner in which they are housing and treating him is appropriate,” he said.

Morrell said that he did not actually speak to Manning but “was just able to see him.” He said he was accompanied by Pentagon general counsel Jeh Johnson.

“There’s this misperception out there that he is in somehow in solitary confinement, out on his own somewhere in a dark and dreary cell,” Morrell said. “That could not be further from the truth.”

Coombs said that although Manning is technically not held in solitary confinement, “the cumulative effect of his confinement conditions are tantamount to solitary confinement.” He said that there are no other detainees on either side of his cell and that the cell lacks a window or natural light. If Manning tries to speak to others several cells away, “the guards will likely view it as disruptive and require him to stop speaking,” he wrote in his blog.

On Friday afternoon, Manning was the only detainee in maximum custody; two other maximum-custody detainees had left that morning, Villiard said.

The jail has 30 cells arranged in a U formation. Though the detainees may talk to one another, the cells are designed so that no detainee has a direct line of sight to another, Villiard said.

On Wednesday, the government denied Manning’s request to be removed from maximum custody and prevention of injury watch, said Coombs, who will appeal.

Villiard said the prevention of injury watch status is reviewed every week with input from mental health providers.

Coombs has asserted that the facility’s forensic psychiatrist recommended that the watch be lifted. A separate psychiatrist hired by the defense concurred, he said.