Did you hear a loud noise last night? These were probably the four helicopters that were seen flying over the skies of Montreal (and Sorel-Tracy) in the evening.
The machines would have crossed Montreal at very low altitude around 9:30 p.m.
The same helicopters were then seen later that night in Sorel-Tracy.
Their passage caused a huge reaction on social networks.
On Reddit, many Montrealers claim that they were military helicopters.