Thousands of flight attendants must still approve the agreement. The walkout, which began Saturday, has disrupted half a million travelers’ plans, the airline said.

Jobs Minister Patty Hajdu says the federal government is launching a probe into allegations of unpaid work in the airline sector as a strike at Air Canada stretches on.

Air Canada said it would reach out via email or text to let customers know if their flights are canceled. The cancellations on Thursday included some long-haul overseas flights. By the end of Friday, the airline expects to cancel 500 flights.