Inmates at the US detention centre at Guantanamo Bay in Cuba have attacked guards after luring them with a staged suicide attempt, the US military said.
Camp 4 is a less restrictive part of the facility
The detainees used weapons crafted from fans and light fixtures and the disturbance was quelled with minimum force, a US military spokesman said.
Six inmates were reportedly hurt in the clash. Earlier two inmates tried to kill themselves with prescribed drugs.
Thursday's incident coincides with a UN call on the US to close down the camp.
The UN Committee against Torture said the US should release detainees or give them access to a judicial process.
The US military has described Thursday's attack as the most violent and best organised in the history of the Guantanamo Bay prison camp.
The BBC's Adam Brookes in Washington says this is the first time that details have emerged of such an incident involving more than one inmate, although individuals regularly resist guards.
The US military said guards responded to an apparent attempt at suicide in Camp 4, a less restrictive part of the facility where detainees are allowed move more freely as a reward for good behaviour.
The facility's commanding officer, Rear Adm Harry Harris said the attempt was "a ruse to get the guards to enter the compound".
He said 10 detainees then attacked the guards as they entered the area, whose floor had been "slickened" with excrement, urine and soap.
Weapons such as broken light fittings and fan blades were used and at one point, another military spokesman said, the guards "were losing the fight".
The violence spread, as other inmates began destroying fittings in their parts of the prison.
The military said it took a team of 23 guards an hour to quell the unrest, using pepper spray and non-lethal shotgun rounds. A spokesman said six detainees were treated for minor injuries and no soldiers were hurt.
None of the detainees involved has been named. All those involved in the clash were removed to higher-security parts of the centre.
Earlier, two detainees are said to have attempted to commit suicide by overdosing on prescription drugs they had been hoarding. Both were reportedly unconscious but in a stable condition.
The military says there have been 39 suicide attempts in the camp since 2002, and hunger strikes have been common as detainees protest against their continued detention without trial.
About 460 detainees are held at Guantanamo, which opened after the US-led invasion of Afghanistan in 2001.
Most detainees are being held without charge or trial, and lawyers who have visited the facility say many of them suffer from depression.
The call by the UN torture committee to close Guantanamo was accompanied by recommendations that secret US detention facilities abroad should be closed.
It called for "immediate measures" to eradicate torture and ill-treatment of detainees by US military personnel "in any territory under its jurisdiction".
John Bellinger, a legal spokesman for the US state department, said the report contained "factual and legal inaccuracies".
Some "acts of abuse" had occurred in the past, he said, but the US was taking steps to prevent any repeat.