Four correctional officers were assault Tuesday at the Sterling Correctional Facility, the Colorado Department of Corrections announced.

According to the release from department spokesman Mark Fairbairn, multiple offenders were involved in the incident in the prison dining hall.

“Staff were examined and emergency treatment was administered by on duty medical personnel,” the release states. “Those injured were transported to the hospital by ambulance and other correctional staff. At this time the facility will remain on lock down as the incident is under investigation.”

Fairbairn said no further details can be released while the investigation is active.