Police, firefighters and ambulance technicians were called to a building Thursday evening at the corner of Ontario Street East and Leclaire Street to deal with a man who was described as agitated and in distress.
Officers closed off the street to traffic as they dealt with the 35-year-old man who was in his apartment and believed to be armed with a knife.
After several hours of negotiating, officers entered the apartment unit where they found the man suffering from cuts to his upper body.
A Sûreté du Québec spokesman said it's believed the injuries were self-inflicted.
The man's life is not in danger.