Pontiac Correctional Center is on lockdown after a staff member suffered non life-threatening injuries at the facility Wednesday.
An Illinois Department of Corrections spokeswoman confirmed the facility is still on lockdown as of Friday afternoon. The IDOC is investigating the incident and declined to provide further information.
A representative with the guards' union said a sergeant was struck in the head with an object by an inmate while touring a gallery in the prison. After the strike, the union representative said he and a lieutenant tried to leave the gallery but were assaulted by other inmates in what was characterized as a planned attack.
The sergeant was reportedly given stitches at a nearby hospital and released.