Military officials said on Friday that the clash erupted on Thursday, the same day two detainees attempted suicide in other parts of the camp.

The battle was one of the most violent incidents reported at the isolated prison, where the US holds about 460 men suspected of links to al-Qaeda or the Taliban. Most of the detainees have been held for more than four years without charge.

Navy Rear Admiral Harry Harris, the prison's commanding officer, said: "This illustrates to me the dangerous nature of the men we have detained here."

The unrest

The turmoil at the detention centre perched above the Caribbean on a US Navy base in southeastern Cuba began on Thursday morning, when a detainee who failed to show up for morning prayers was found unconscious in his cell, Harris said.

Tests indicated he had taken an overdose of drugs similar to the anti-anxiety drug Xanax. He was hospitalised in a serious but stable condition.

Early in the afternoon, guards searching the prison for contraband prescription medicine found another detainee "frothing at the mouth" from an overdose of drugs.

 "Under these circumstances, it's hardly surprising that people become desperate and hopeless enough to attempt suicide" 

Joshua Colangelo-Bryan,
lawyer for a Bahraini detainee

He was also hospitalised in a stable condition, the admiral said.

In the early evening, guards had spotted a detainee in Camp Four, a medium security, communal-living unit for the "most compliant" prisoners, apparently preparing to hang himself with a bed sheet tied to the ceiling of the room he shared with nine detainees.

Army Colonel Michael Bumgarner said that the detainees, who had made the floor slippery with faeces, urine and soapy water, attacked 10 members of Guantanamo's quick-reaction force with fan blades, pieces of metal and broken light fixtures when the team went to investigate.

For several minutes the detainees appeared to have the upper hand, knocking some of the soldiers to the ground in the struggle, Bumgarner said.

Outside, Guantanamo officials mustered 100 more guards before the force gained control using pepper spray, unspecified physical force, five blasts of a shotgun that fires rubber pellets and one shot from a non-lethal weapon that Bumgarner said fires a sponge-like projectile.

Detainees in two other units of Camp Four began damaging security cameras, light fixtures and other items in their rooms in a show of support for those engaged in the melee, officials said, doing an estimated $110,000 in damage.

Despair

Six detainees had minor injuries and no guards were injured, Harris said. The prisoners involved were moved to a higher security area.

Officials say there have been 41
suicide attempts at the prison

The authorities did not provide the names or home countries of those involved.

Defence lawyers said the suicide attempts reflect increasing despair among detainees.

Joshua Colangelo-Bryan, a lawyer for a detainee from Bahrain who has repeatedly tried to kill himself, said: "Under these circumstances, it's hardly surprising that people become desperate and hopeless enough to attempt suicide." 

Also on Thursday, the military transferred 15 Saudi detainees to their country, but Harris said he did not think there was a connection.

Guantanamo officials said there had been 41 suicide attempts by 25 detainees but no deaths since the camp opened.