That's according to the BBC, which also reports that a "couple of dozen detainees" have chronic psychiatric problems. Some are reported to have cut themselves with plastic utensils; others are said to have banged their heads against the walls.
None of the attempts are reported to have caused serious injuries, and a military official at Guantanamo says in some cases, the actions of the men are viewed as a sign that the detainees are showing remorse for their earlier deeds as members of al Qaeda and the Taliban.
Word of the state of mind of Guantanamo Bay detainees captured in the war in Afghanistan came as the Bush administration continued to joust in court over the issue of what rights detainees - and other terror suspects - have or ought to have.
There are currently 598 detainees at Guantanamo, including several dozen who have arrived in the past few days.
They're called "detainees" because the Bush administration takes the position that they are not soldiers for any sovereign nation and are therefore not subject to all of the conditions in the Geneva Convention regarding the appropriate treatment of prisoners of war.
One thing authorities have sought to avoid is holding any captured Americans at Guantanamo.
John Walker Lindh, the American-turned-Taliban soldier who struck a plea bargain with the feds last month, has been held in Virginia, as is Yasser Esam Hamdi, a Louisiana-born 21-year-old accused of being a soldier in the al Qaeda war on America
Hamdi's case came up in federal court in Norfolk, Virginia, Tuesday, in what is viewed as a test case on the limits of government power to hold its citizens indefinitely without trial and without a lawyer.
Hamdi was captured in Afghanistan in November after a prison uprising by suspected Taliban and al-Qaida members. He was transported along with hundreds of other alleged enemy soldiers to a makeshift prison at the U.S. Navy base at Guantanamo Bay, Cuba.
The military transferred him to the Navy brig in Norfolk, Va., after determining he was telling the truth about his birth in Baton Rouge, La., while his Saudi father worked there.
Now he is the subject of a power struggle between the Bush administration and a federal judge, appointed by former President Ronald Reagan, who has ruled that Hamdi has, at least, the right to see a lawyer.
"So, the Constitution doesn't apply to Mr. Hamdi?" U.S. District Judge Robert G. Doumar snapped during a testy standoff with Justice Department lawyers Tuesday.
CBSNews.com Legal Analyst Andrew Cohen says the judge was apparently displeased by the prosecution's reluctance to provide detailed answers to questions the judge posed about "why the government considers Hamdi an 'enemy combatant,' why it moved him from Afghanistan to America, what he was doing when he was captured and other relevant facts" for him to consider before signing off on Hamdi's indefinite detention.
Legal scholars say if Hamdi can be imprisoned in a military jail with few of the constitutional protections afforded Americans facing criminal prosecution, then other U.S. citizens could be similarly held.
The Justice Department calls Hamdi an enemy combatant, a somewhat elastic term generally describing a wartime prisoner who does not play by the rules of war and is thus ineligible for protection as a prisoner of war. Those prisoners may be held without charges or trial and interrogated humanely without a lawyer present. They are supposed to be released when the war is over.
A federal appeals court is awaiting word from Doumar about Hamdi's status, and the case is seen as likely to wind up before the Supreme Court.
The high court could settle constitutional questions about the indefinite detention of U.S. citizens or whether the courts have veto power over the White House when it comes to deciding who is an enemy prisoner.
For the government, the stakes in the Hamdi case turn on how fully the rules for enemy combatants apply to those born in the United States or who assume citizenship later. Prosecutors would prefer to keep all enemy combatants out of U.S. courts, where they fear judges might order the prisoners released or where the government might be pressed to reveal sensitive intelligence information.
The government maintains the power to classify someone an enemy combatant resides with the president and that courts have little role to play. The Justice Department has stonewalled Doumar, refusing to give him details about Hamdi's alleged activities or capture that the judge has said he needs.
Hamdi is not the first U.S. citizen classified by the government as an enemy combatant, but his case is nonetheless unique. A German saboteur caught on U.S. shores during World War II also was a U.S. citizen, but he was given a lawyer and tried before a military tribunal.
A federal public defender has signed up to represent Hamdi, but so far has not been allowed to either meet or talk with his client.