The site was shut down six times in a three month period because someone had called in saying they'd left a bomb on the site.
There were also scares at the Sainte-Justine university hospital site.
During these incidents, the construction sites were cleared out and workers sent home while bomb squad technicians and sniffer dogs conducted searches, costing thousands of dollars in lost man-hours.
Police arrested the men in the Chomedy section of Laval Tuesday night, as a result of the investigation that began in May.
One of the suspects, 29-year-old Edison Saintil, has already appeared in court to face accusations of public mischief and making false 911 calls.
Police say Saintil will likely face additional charges and they expect to make more arrests.