LITTLE ROCK, Ark. (AP) — Arkansas officials on Thursday identified the three correction officers who were held by several inmates in part of a prison for about three hours earlier this week after the prisoners snatched the officers' keys and a Taser.

The Department of Correction said Lt. Willie Carmickle, Sgt. Levester Johnson and Correctional Officer George Thomas were held by the inmates at the Maximum Security Unit in Tucker on Monday. The department has not identified the inmates, who released the officers and surrendered.

The agency also has not said how the inmates overpowered the officers, nor how they obtained the keys, Taser and other equipment. A prison spokesman earlier this week said that lieutenants, captains and majors were authorized to have Tasers, and said Thursday he did not know whether Carmickle had one.

The department said Carmickle has been an employee since February 2010, Johnson since March 2006 and Thomas since January. The three officers were not placed on leave by the agency, but have not returned to duty since Monday's incident, department spokesman Solomon Graves said.

The incident is the subject of investigations by the department, the state Board of Corrections and Arkansas State Police. Text messages released earlier this week revealed that a prison handcuff key was found on a bus that transferred the inmates from Tucker to another facility after the incident. The department has said the inmates were searched when they arrived at the other facility, Varner Supermax, and there was no indication they brought keys or any other prohibited item into the facility.

The disturbance occurred a little over two weeks after a guard at the same prison fired three warning shots in the air after two guards and an inmate were attacked. The department and state police are also investigating that incident.

In a separate incident, the department said an inmate who was injured in an assault at another prison last month died early Thursday. John Demoret was pronounced dead at 6:15 a.m. Thursday after being transported to a hospital from the Ouachita River Correctional Unit in Malvern. Demoret was serving a 10-year sentence for manslaughter out of Hot Spring County.

Corrections officials said Demoret, 25, was assaulted at the Tucker Unit — which is a separate facility from the maximum security unit — on July 28. Officials did not disclose details of the assault or the extent of Demoret's injuries.

State Police officials launched an investigation after they were notified of the assault. Corrections officials said investigators have been notified of the inmate's death. The Department of Corrections said it is also conducting an internal investigation.