Multiple Canadian airports faced bomb threats Thursday morning that grounded flights and are expected to cause widespread delays, according to air traffic control manager Nav Canada."Early this morning,

Major Canadian airports are returning to normal operations after they were forced to delay some morning flights on Thursday because of bomb threats.The threats affected facilities in Ottawa, Montreal,

Nav Canada said the early morning threats affected airports in Ottawa, Montreal, Edmonton, Winnipeg, Calgary and Vancouver. Airports are returning to normal operations after Canada’s air traffic control service said YVR and some other airports received bomb threats early Thursday morning.