A 52-year-old Niagara officer has been critically injured in a shooting, following an “altercation” between two officers, according to Ontario’s Special Investigations Unit (SIU).

The incident occurred in Pelham, Ont., about 30 minutes west of Niagara Falls.

In a statement, Niagara Regional Police said there was “an incident in Pelham involving members of the NRPS.” The force said that an officer was transported by paramedics.

The SIU confirmed Thursday afternoon that the agency was investigating “an interaction between two Niagara Regional Police Service officers” and that one of the officers sustained a gunshot wound.

At a news conference Thursday evening, SIU spokesperson Monica Hudon said that the officers were in the area of Effingham Street and Roland Road conducting an investigation into a collision that occurred a few days earlier.

“Around noon, there was an interaction between two of the officers and one of the officers was struck by a gunshot,” she said. “Understanding what transpired and the relationship between the officers is part of the SIU’s investigation. I can only tell you that there was an altercation and a firearm was discharged and an officer was struck.”

Ornge air ambulance confirmed that one person was picked up in St. Catharines and was transported to Hamilton General in critical condition.

Hudon said that the injured officer remains in critical condition at the hospital.

No other information was provided by the SIU about the other officer involved in the incident or what led to the firearm discharge.

The SIU has invoked its mandate and has assigned eight investigators and three forensic investigators to the case.

The agency investigates incidents involving serious injuries, deaths and allegations of sex assault involving police officers.

Niagara Regional Police Chief Bryan MacCulloch said in a statement that no arrests have been made in connection with this incident.

“The investigation is in the hands of the Special Investigations Unit. In the spirit of transparency, I have asked the Ontario Provincial Police to determine if there is any criminal culpability outside of the SIUs scope.”

Hudon is asking anyone who may have seen the incident or who may have video footage of the area to contact investigators at 1-800-787-8529.