Canada’s air-traffic control agency is warning travellers across Canada Thursday to check with their airlines for flight-schedule disruptions.

NAV Canada says it is responding to threats made to its facilities at airports across the country. The agency is not naming specific airports at this time.

“Early this morning, NAV CANADA was made aware of bomb threats affecting several of our facilities. Employees at impacted locations were safely evacuated, and a temporary ground stop has been implemented at the affected airports,” said spokeswoman Vanessa Adams.

“We are collaborating with authorities to address the situation and ensure the safety of all personnel and passengers. Travellers are advised to check directly with their airline for the latest updates, as delays may occur.”