By Allison Lampert and Ismail Shakil
MONTREAL/OTTAWA (Reuters) -WestJet Airlines and air traffic control manager NAV Canada said their services were returning to normal on Thursday afternoon following earlier outages that led to long airport lines and 100 delayed flights.
WestJet Airlines said it had restored check-in and gate services hit earlier in the day.
The country's largest airports are already wrestling with delays and lost luggage as staff struggle to keep up with an unexpectedly strong rebound in air travel after a pandemic-induced slump.
Canada also said on Thursday it would resume random COVID-19 testing for inbound international air passengers effective Tuesday, after about a month-long pause. Testing sites will be moved outside airports to reduce congestion.
Passengers flying privately-held WestJet took to social media to post images and accounts of hours-long lines at airports, such as at Canada's busiest, Toronto Pearson International Airport.
"Across our network we have seen three cancellations and more than 100 flights have been delayed as a result of the outage," WestJet said in a statement.
NAV Canada attributed the outage to Zayo Group Holdings, Inc., one of its telecommunications services providers.
Zayo a communications infrastructure platform, said the outage was caused by the disruption of two key fiber lines, partly because of a train derailment on Wednesday night.
"We have rerouted a significant volume of traffic via other routes so that our customers can begin resuming normal operations," said Zayo, which provides bandwidth to customers including the tech and finance industries.
Earlier on Thursday, the Greater Toronto Airports Authority (GTAA), which operates Toronto's Pearson, cited long lines at one of its terminals due to the outages, while Calgary International Airport said travelers may experience delays.
Last week, a massive network outage at Rogers Communications Inc disrupted nearly every facet of life in Canada, including the call center service of the country's largest airline Air Canada.
The federal government said this week that Canada's telecom networks need to be more resilient and asked telecommunications companies to agree to a formal deal to help each other during emergencies.
(Reporting by Ismail Shakil in Ottawa and Allison Lampert in Montreal; editing by John Stonestreet, Chris Reese, Richard Chang and Diane Craft)