On Twitter the Police Montreal account posted: "There is an ongoing police operation at the corner of Saint-Laurent and St-Viateur".
As for what started all of this, the main culprit at this time seems to be a 911 call that was fraudulent. Specialized #SPVM officers are on site inspecting the premises. Ubisoft employees were filmed protecting themselves on the roof of their office building, and images of the scene were widely circulated online.
ADDITIONAL UPDATE: Some Ubisoft Montreal team members have reported getting out safely. Montreal police have also said the debacle is over, that no one was injured, and that an investigation into the call will be made. We are now evacuating the building.
"The police operation in connection with a hostage taking call is over". IGN will have more updates as the situation continues to unfold.
"We are aware of the situation and working with local authorities", a spokesperson for Ubisoft said in a statement to Windows Central.
It's unclear what exactly the threat was or where it came from but multiple local outlets described it as a hostage situation.
A Code Orange is a rare alert system used when medical staff need to prepare for the possibility of mass injuries.
No one has been injured. It is worth noting that other non-Ubisoft entities work inside that facility, too. He said all questions about the incident should be directed to police.
Various reports spread throughout Montreal on Friday afternoon about what was happening at Ubisoft. As such, the police began evacuating the building and guiding Ubisoft Montreal employees to safety, away from the building.
Montreal Mayor Valerie Plante said on Twitter that the city was in contact with police, asking people to avoid the area.
Montreal police have not confirmed whether the people seen on the roof are hostages.
Ubisoft has multiple buildings in the area. Others said they were either were safe despite the circumstances.
When she left at about 2:20, "the parents were still waiting outside", she said.