A system-wide computer outage is leading to long lines at airports across Canada on Monday, as some flights are having to be checked in manually.

Social media is full of reports of long lines at airports, including those in Vancouver, Toronto, Montreal and Calgary.

The company is telling passengers it is experiencing “an interruption” with the check-in process, and online at aircanada.com

“We apologize for any inconvenience and are working towards restoring our service as quickly as possible,” the airline said on Twitter.

Customers in foreign airports have also been raising concerns about long lines and check-in delays, but it’s not immediately clear how far the outage extends.

The airline has not immediately replied to a request for comment from CBC News.

The disruption comes two weeks after the airline had a computer issue that disrupted web and mobile check-ins and call centre operations and temporarily delayed boarding on some flights.

With files from The Canadian Press