By: The Canadian Press

Thousands of Canadian travellers could see delays Thursday after the country’s air traffic control service said some airports received bomb threats.

Nav Canada said the early morning threats affected airports in Ottawa, Montreal, Edmonton, Winnipeg, Calgary and Vancouver.

It said employees at the airports are safe and there was a temporary ground stop.

Service is gradually resuming after “the evacuation of number of our sites” and threat assessment by authorities, the agency said in a social media post.

“We thank airlines and passengers for their patience as we work towards normal operations,” it said.

The Ottawa airport said early Thursday that it was investigating a “security incident” and operations could be disrupted.

As of just after 9 a.m., the airport’s website was showing that several flights were delayed.

Travellers are advised to check the status of their flight before heading to the airport.