A lockdown remains in place at Stony Mountain Institution after three inmates were assaulted at a medium security unit Thursday night.
In a statement the Correctional Service of Canada said the three injured inmates were found around 7:40 pm.
The extent of the injuries have not been released.
The injured inmates were evaluated by staff and transported to an outside hospital for treatment.
The Warden ordered a lockdown and a general search of the medium and maximum security units.
Visits to the prison have also been suspended until the search is complete.
The Institution, the Stonewall detachment of the RCMP and CSC are investigating.
No staff members or other inmates were injured during the incident.
The lockdown will be lifted and normal operations will resume, once it is considered safe to do so.