Montreal - Television images showed the streets around the old brick building cordoned off by heavily armed officers
A major police operation was underway in Montreal on Friday at offices of French video game company Ubisoft that local media reported was a possible hostage-taking.
Dozens of people have reportedly been taken hostage, media worldwide reported.
Police confirmed the massive deployment on Twitter had started at about 1:30 pm local time, but offered no details while urging people to "avoid the area" near St-Laurent Boulevard and St-Viateur Street in Montreal's Mile-End neighbourhood, close to downtown.
Local newspaper The Journal Montreal reported on Friday that the hostages were in the Ubisoft office.
Some employees were able to get out of the building but some remain there and are taking refuge on a terrace, on the other side of fire doors.
Television images showed the streets around the old brick building cordoned off by heavily armed officers, and dozens of Ubisoft workers who appeared to have barricaded themselves on the rooftop.
"Police officers were dispatched to the scene to respond to a 911 call," a police spokesperson told AFP.
"The information has still not been validated," the official said, adding that "officers specialising in this type of intervention are currently on the scene and are carrying out checks."
"No injuries were reported."
Montreal Police released the following statement: “Officers have been sent to the location following a 911 call. Specialized SPVM officers are on site inspecting the premises. There are no injuries reported.”