Four terror suspects being held at the U.S. naval base in Guantanamo Bay tried to kill themselves in their cells, a military official said Thursday.

One man tried to slash his wrists with a plastic razor, and three others tried to hang themselves with "comfort items" at Camp Delta, the prison in eastern Cuba where 598 men are being held, said Army Lt. Col. Joe Hoey, a detention mission spokesman.

The suicide attempts occurred in July and August, but military spokesmen gave no details on exactly what they used or how seriously they were hurt. Comfort items include towels and sheets.

"All of these men are monitored very closely and their attempts were not successful," Hoey told The Associated Press. Hoey said all four had returned to their cells.

Since the first detainees arrived in January, none have been charged by the U.S. government, which says it may try them in military tribunals, send them home or hold them indefinitely. The detainees are being interrogated and are not allowed lawyers.

The legal limbo has outraged human rights activists and psychologists who say the uncertainty the men face is unbearable and counterproductive to interrogators seeking information.

"Once you're in that condition, you're not rational," said psychiatrist Stuart Grassian of Harvard University in Boston, an expert on the affects of long-term confinement in maximum-security conditions.

"Leaving people in confinement, or pushing them to the breaking point, won't necessarily improve the ability to get information," Grassian said. "When people break, a lot of times it isn't in a way that's particularly useful to anyone."

Dozens of detainees, who represent 38 countries, have staged hunger strikes to protest their indefinite detentions. Others are being treated for psychological disorders and several are being medicated with antidepressants or anti-psychotic drugs.

Many of the men have made statements that they wanted to die or kill themselves, Hoey said, and several others have tried to harm themselves, but the actions were not considered suicide attempts.