A prisoner unlocked his cell door, overpowered a guard and freed dozens of maximum-security inmates today at a South Texas prison where a corrections officer was stabbed to death Friday.

Although 80 inmates escaped from their cells, they never got beyond their cellblock. Riot teams regained control of the maximum-security area four hours later.

Prison officials said they did not believe the disturbance at the McConnell Unit was related to the slaying of a 37-year-old guard, which occurred in a minimum-security area of the prison.

Glen Castlebury, a spokesman for the Texas Department of Criminal Justice, said the inmate who attacked the control room guard may have tricked the officer by offering to hand over contraband. The prisoner then opened the cell doors and smashed the control panel as the guard and two other correctional officers fled.

"The officer in the control room apparently opened his door and the inmate then grabbed that officer and cut him on the forearm with a weapon," Castlebury said. "The inmate got into the control room [and] . . . electronically opened all 84 of the cell doors."

Eighty of the 83 inmates emerged from their cells shortly after 3:30 a.m. Prison riot teams moved in about 5 a.m. with gas and batons and brought the situation under control by 7 a.m.

One officer was taken to a hospital with cuts on his forearm.

Beeville is about 90 miles southeast of San Antonio.