US airline giant Delta has suspended departing flights worldwide after suffering a major system outage.
“Customers should check the status of their flight before heading to the airport while the issue is being addressed,” the company tweeted.
It said it was working to resolve the problem as soon as possible. Inbound flights en route are not affected.
Delta ranks third in the world in terms of most passengers carried, according to industry body the IATA.
What caused the outage or how long it will take to resolve has not been released.
London’s Heathrow airport said: “Delta flights from Heathrow are experiencing delays due to the worldwide technical issue with their computer systems.”
“Check-in is currently operating using a back-up system and airport staff are on hand to assist any passengers that are impacted by the delays.”