Guards at the Guantanamo Bay prison fired non-lethal shots to quell prisoner unrest Saturday as they relocated inmates into individual cells, US military officials said.

Officials at the US-run prison met with resistance from some inmates as they moved before dawn to relocate inmates from communal housing into individual cells.

"Some detainees resisted with improvised weapons, and in response, four less-than-lethal rounds were fired," according to a statement from Robert Durand, a spokesman with Joint Task Force Guantanamo, which runs the prison.

He said there were "no serious injuries to guards or detainees" during the operation aiming "to reestablish proper observation" at the facility.

The shots fired came from two crowd-dispersal rounds about the size of a pea and two rubber bullet rounds known as the M1012 Non-Lethal Point Control Cartridge.

Each crowd-dispersal round contains 18 rubber balls of .32 caliber with "limited ability to penetrate skin and little ability to cause injury," according to Durand.

The last time non-lethal shots were fired at Guantanamo was on January 2, against a group of detainees who were throwing rocks. One prisoner was hit by one of the crow-dispersal rounds.

Durand's statement added that the decision to isolate the inmates had been made "to ensure the health and security" of prisoners at the facility in Cuba, where dozens of detainees are in the third month of a hunger strike.

Housing detainees in individual cells will allow US officials to "observe them more closely," he said, adding that only detainees who comply with camp rules and procedures will now be allowed to share living spaces.

"Suspending the detainees' communal living privileges was in response to a coordinated effort by detainees to create an unsafe situation and limit the guard force's observation by obscuring and covering surveillance cameras, windows and glass partitions," the statement added.

The facility in Cuba houses scores of prisoners swept up more than a decade ago during in America's so-called war on terror.

"Round-the-clock monitoring is necessary to ensure security, order and safety, as detainees continued a prolonged hunger strike by refusing regular camp-provided meals."

The strike began when the men claimed prison officials searched their Korans for contraband. Officials have denied any mishandling of Islam's holy book.

An attorney representing some of the inmates decried their treatment.

"It's just another example of force being used in GTMO (Guantanamo), instead of a sense of human rights," said military lawyer Lieutenant Colonel Barry Wingard.

"The sad thing is that it doesn't appear to matter which political party is in power in Washington. The officials in GTMO always resort to force over common sense."

He said the prisoners had asked prison officials to take their Korans instead of "disrespecting" them.

"The officials refused to take the Korans, and continued to search the books in plain view of the prisoners," Wingard added.

"Of course, the bigger issue is the 11.5 years without charges and hopelessness of never being released."

Attorneys representing inmates at the prison have said that most of the estimated 130 detainees at Guantanamo's Camp Six wing, which houses "low-value" prisoners, are on hunger strike.

US authorities, however, put the number of hunger strikers at about three dozen.

Durand said medical staff were providing intravenous fluids and supplemental nutrition such as enteral feeding "if necessary" when detainees are at risk of death or "serious self-harm."