TORONTO >> Air Canada says an illegal job action by some of its pilots is causing cancellations and delays across the country.

Canada’s largest airline issued a Canada-wide travel alert on Friday, warning “airport disruptions” could affect flights all day and into the weekend.

Spokesman Peter Fitzpatrick says about 30 flights have been cancelled out of the roughly 1,500 scheduled each day.

He wouldn’t confirm the nature of the job action, but reports say a small group of pilots are staging a “sick-in” to express their displeasure with airline management.

Air Canada has been embroiled in several labor disputes over the past few months, including with its 3,000 pilots.