The Alberta Children's Hospital was locked down and a perimeter of roads closed after a report of a firearm complaint drew a huge response from first responders Sunday evening, Calgary police tell CBC News.

Police responded with multiple units, including canine and HAWCS helicopter support, to the northwest hospital at about 8:20 p.m., police said.

The facility was put in lockdown mode as a precaution and police and security personnel swept the building floor by floor, but nothing was found.

Police say the investigation continues. Similar calls were made around the same time Sunday night to hospitals in Edmonton and Toronto, police say.