HOLDENVILLE, Okla. (AP) — Officials say a corrections officer has died after being attacked by an inmate at an Oklahoma prison.

The attack happened Sunday at the Davis Correctional Facility, which is a privately run prison in Holdenville about 70 miles southeast of Oklahoma City.

Officials say the inmate attacked the officer while a group of inmates was returning to a housing area from recreation. Authorities have not identified the officer or released a cause of death. The inmate has been placed in isolation and an investigation is underway.

The prison is a medium-security facility and is operated by CoreCivic.