What to know about tonight's mock explosion drill at Pearson Airport

Toronto's Pearson International Airport will hold a large security exercise late Saturday night, but travellers should expect few disruptions or delays, an official says.

Emergency personnel, airport staff and more than 100 volunteers are testing the airport's emergency response by running a mock bomb threat and explosion at Terminal 1 between 11 p.m. Saturday and 3 a.m. Sunday.

The drill was scheduled overnight to cause as little disruption as possible to passengers flying in and out of the terminal, airport spokesperson Sean Davidson said.

He says departing travellers should be able to get through security and on their flights without delays.

'As real as possible'

Terminal 1 will have signs to let travellers know a drill is underway, Davidson says, but they should expect lots of action once it begins.

"We make it as real as possible because we want to test our response to potential emergencies at the airport," Davidson said.

"These exercises happen every year, and we take valuable lessons away from them. And then we refine our protocols and procedures to make sure that the airport remains a safe space."

The airport runs annual exercises like Saturday's to test responses to different emergency situations, as is mandated by Transport Canada.

Davidson says travellers can expect to notice a larger presence of Peel Regional Police officers, emergency personnel, airport staff and volunteers starting around 7 p.m.