Officials at the Oregon State Department of Corrections said Friday an inmate was shot and killed by a guard during a fight at the facility in Pendleton.

The Eastern Oregon Correctional Facility near Pendleton is on lockdown until further notice after Jason Matthew Withers was fatally shot while assaulting another inmate.

Withers and another inmate were beating another prisoner Friday morning, and apparently ignored warning shots to stop.  Withers was struck by a bullet fired across the yard by a corrections officer.  The assaulted inmate was treated at a local hospital for his injuries, the extent of which was not released.

The other inmate participating in the assault, say officials, is currently in segregation.  Visitation has been cancelled, and the investigation continues by several Oregon law enforcement agencies.