Three Edmonton Institution inmates are facing charges following two assaults at the maximum security prison on Dec. 28.

In the first incident, a 49-year-old inmate was assaulted in a cell at about 5:10 p.m., say Edmonton police and Correctional Service Canada (CSC.)

The inmate was taken to hospital with non-life threatening injuries.

Police said a weapon was used in the assault.

"He did require medical attention at an outside hospital, so it would lead me to believe that he's got reasonably serious injuries that need looking after," added Jeff Campbell, a spokesperson for CSC.

Two men, 22 and 26, face charges for the alleged assault.

Around 6:45 p.m. the same day, a fight broke out in a separate living unit.

A 30-year-old inmate was treated in hospital for non-life threatening injuries.

A weapon was used in the second fight. Police wouldn't say what kind.

Another 26-year-old man faces charges for the second alleged assault.

"We have not confirmed that they are related," Campbell said of the two incidents.

No CSC employees were injured in dealing with either incident, Campbell noted.

"The staff did intervene to stop those disturbances," he said. "That would be their role."

The institution was locked down for a day. Inmates were confined to their cells.

Besides the criminal charges, the inmates may face disciplinary action.

"We don't tolerate violence in institutions, and we're going to examine each incident when some violence does occur," Campbell said.

Both CSC and Edmonton police are investigating.