Months of increased tension at the Guantanamo Bay prison boiled over into a clash between guards and detainees Saturday as the military closed a communal section of the facility and moved its inmates into single cells.

The violence erupted during an early morning raid that military officials said was necessary because prisoners had covered up security cameras and windows as part of a weeks-long protest and hunger strike over their indefinite confinement and conditions at the U.S. base in Cuba.

Prisoners fought guards with makeshift weapons that included broomsticks when troops arrived to move them out of a communal wing of the section of the prison known as Camp 6, said Navy Capt. Robert Durand, a military spokesman. Guards responded by firing four "less-than-lethal rounds," he said.

There were no serious injuries from the rounds, which included a modified shotgun shell that fires small rubber pellets as well as a type of bean-bag projectile, said Army Col. Greg Julian, a spokesman for Miami-based U.S. Southern Command, which oversees the prison at the U.S. base in Cuba.

"I know for sure that one detainee was hit but the injuries were minor, just some bruises," Julian said.

The confrontation came a day after a team from the International Committee of the Red Cross finished a three-week visit to Guantanamo to meet with prisoners and assess conditions.

"The ICRC continues to follow the current tensions and the hunger strike at Guantanamo very closely and with concern," spokesman Simon Schorno said. "If necessary, an ICRC team will in coming days return to Guantanamo to assess the situation of the detainees on hunger strike in view of this latest development."

166 prisoners remain

Camp 6 had previously been a section of the camp reserved for detainees who followed prison rules. In exchange they were allowed to share meals and pray together, have nearly round-the-clock recreation time as well as access to satellite TV, computer games and classes. It held a majority of the 166 prisoners at the base before the hunger strike began, but the military said the number was down to fewer than 70 on Saturday.

The guards moved the hunger strikers and all other detainees at the communal section to single cells in a separate wing of Camp 6 around 5 a.m. Prisoners will eventually be allowed back into communal living conditions in the future if they follow rules, while hunger strikers will be held in single cells, Durand said.

"For now, housing detainees in individual cells will enable us to observe them more closely," he said.

Tensions had been high at the prison for months. Lawyers for prisoners said a hunger strike began Feb. 6 in protest over their indefinite confinement and what the men believed were tighter restrictions and intrusive searches of their Qurans for contraband. Prisoners offered to give up the Muslim holy book that each one is issued by the government but officials refused, considering it a tacit admission of wrongdoing.

"This is exactly the opposite of what they should be doing," Carlos Warner, a federal public defender in Ohio, said of the decision to move prisoners into single cells instead of negotiating an end to the strike. "The military is escalating the conflict."

The military said 43 prisoners were classified as hunger strikers under a definition that includes missing nine consecutive meals. Lawyers for prisoners have insisted the strike is much more widespread and say almost all of the men are refusing to eat.

Officials were also concerned that some men were surreptitiously starving themselves to avoid being classified as hunger strikers and force fed. The military said it was conducting individual assessments of all the prisoners.