Correctional Service of Canada and Northumberland OPP are investigating an assault at Warkworth Institution.
Regional Communications Manager Kyle Lawlor says an inmate was assaulted on Sunday afternoon at the medium security prison.
The injured inmate was taken to the hospital to receive treatment.
No staff at the federal facility or other inmates were injured during the incident.
CSC says appropriate actions have been taken against the assailant in the assault.
