Operations are back to normal after multiple Canadian airports faced bomb threats on Thursday morning that grounded flights and were expected to cause widespread delays, according to air traffic control manager Nav Canada.

Passengers at YVR are being told to anticipate some delays after a security threat at a number of airports nationwide on Thursday. NAV Canada first shared news of the bomb threats around 5:30 am, saying its facilities at airports like Vancouver and Montreal had been evacuated and that all staff were safe.