ATMORE, Ala. — Some corrections officers are not showing up for work at a crowded south Alabama prison that has been beset by multiple incidents of violence.

Department of Corrections spokesman Bob Horton said six corrections officers assigned to William C. Holman Correctional Facility in Atmore called in sick for the third shift Sunday. Nine officers did not for show up for the same shift on Sept. 24, according to the prison system. Three officers resigned.

Horton says officers have not announced an official strike or given demands to prison administrators. However, Horton said officers’ concerns expressed to media about the facility are “understandable due to understaffing and overcrowding.” Officers from other prisons have been brought over to fill in at the prison, he said.

Located in southwest Alabama, the maximum-security prison houses the state execution chamber and has been the site of multiple outbreaks of violence.

A Holman officer died last month after being stabbed by an inmate.

Inmates injured the warden, set fires and seized control of dormitory during a March uprising. The prison was placed on lockdown again in August after officials said inmates in one of the dormitories “became aggressive” toward the guards. Officers secured the door of the housing area, and some inmates inside started a fire inside.

A Department of Corrections report shows Holman was designed to hold 581 inmates but housed 804 inmates at the end of May.