Four corrections officers suffered minor injuries Tuesday afternoon in a disturbance in a mess hall at Attica Correctional Facility, a state spokesman said.
A union official speculated that the melee may have been triggered by a gang initiation that requires prospective members to harm a prison guard.
An inmate attacked a corrections officer with his hands, and three more inmates tried to join in, authorities said. About 270 inmates were in the mess hall at the time.
Prison officials quelled the incident by releasing a chemical agent similar to tear gas, according to Mike Houston of the state Department of Correctional Services.
The injured officers, who suffered cuts, bumps and bruises, were taken to Genesee Memorial Hospital in Batavia. Houston said they were treated and released.
After the 4:30 p.m. disturbance, the inmates were moved to a secured yard for decontamination, then frisked as they re-entered the cellblock. A lock-down was imposed at 6:30 p.m. and was expected to continue for at least all of today as the investigation progresses, Houston said.
The attack may have been gang-related, according to Robert Lawson, spokesman for Council 82 of the American Federation of State, County and Municipal Employees, which represents 21,000 corrections officers.
"If you assault an officer, you can get in the gang. This is a problem that has come up at other facilities," he said.
Lawson said officers arriving for the afternoon and evening shifts reportedly had been warned at roll call about potential trouble in a mess hall.
"But they didn't hold any officers over from the day shift or call any officers in," Lawson said. "This is something we will be looking into very closely."
Corrections spokesman James Flateau in Albany called Lawson's comments irresponsible.