JACKSON, Miss. (AP) — Ten people have been indicted for their roles in a riot at a prison in Natchez that left one guard dead, federal authorities said Wednesday.

The indictments, announced Wednesday by FBI Special Agent In Charge Daniel McMullen and U.S. Attorney Gregory K. Daniels, are in addition to nine others previously charged in connection with the May 20, 2012, riot at the privately-run Adams County Correctional Center.

The prison is owned by Nashville, Tenn.-based Corrections Corporation of America, one of the nation’s largest private prison companies.

McMullen and Daniels said the defendants were charged with instigating, conniving, willfully attempting to cause, assisting, or conspiring to cause any mutiny or riot at a federal correctional facility.

Indicted were: Gerson Benavides, 29; Adrian Romero-Carrera, 27; Carlos Flores, 40; Ruben Coronado-Licon, 22; Ricardo Quintana, 28; Margarito Munoz-Astello, 36; Bertil James, 38; Ian Jeffrey Reid, 43; Haisam Ali, 36; and Raybell Granillo, 28.

During the riot, several corrections officers were assaulted and one officer, Catlin Carithers, died from injuries he received. Other guards were held hostage for several hours.

It took hours for authorities to suppress the riot, which caused an estimated $1.3 million in damage.

Prosecutors have said that Marco Perez-Serrano, also known as Jesus Fernando Ochoa, was the first inmate to attack Carithers during the riot. Carithers died and 20 people were injured as the riot grew to involve hundreds of inmates.

Perez-Serrano pleaded not guilty in April to a charge of rioting. A change of plea hearing is scheduled for Aug. 13 in U.S. District Court in Natchez.

Inmate Jesus Beltran-Rodriguez, also suspected of beating Carithers, and Humberto Cuellar, accused of taking a different guard hostage during the uprising, are scheduled for trial Oct. 7. They have pleaded not guilty to rioting.

The prison holds nearly 2,500 inmates, most of them convicted on charges of coming back to the U.S. after deportation for being in the country illegally.