BBCNo flights are able to take off or land at Edinburgh Airport due to an IT issue affecting air traffic control.
An airport spokesperson said engineers are currently working to fix the issue while many incoming flights were diverted elsewhere.
Passengers have been advised to check the status of their flights with individual airlines before coming to the airport.
A further update is expected later.
Flights have been cancelled or diverted for several hours including the following flights which will land at Glasgow Airport.
- Loganair flight LM316 from Exeter
- Easyjet flight EZY601 from Luton
- Ryanair flight FR6643 from Bratislava
- British Airways flight BA1462 from London
- Easyjet flight EZY3264 from Munich
- Ryanair flight RK860 from Agadir
- Ryanair flight FR2885 from Kaunas
A 15:30 Turkish Airlines flight from Istanbul and a 16:05 Ryanair flight from Gran Canaria have been diverted to Manchester Airport.
Andrea Racekova, an apprentice journalist for BBC News, is among those affected by the cancellations.
The 26-year-old travelled from Shetland to Edinburgh in order to catch a flight to her home in Slovakia for an important blood test she has been waiting months to receive.
Reporting from the scene, she said: “I found out about the whole issue through Ryanair staff at the gate after we’d been asked to queue up for boarding.
“We were asked to sit down as the flight wouldn’t leave for at least another 30 minutes, but that was over an hour ago.”
Andrea waited for news but now her flight has been cancelled altogether – she has heard there will be “indefinite delays” for other flights.
She said: “People around me are very frustrated, some of them have connecting flights to catch, so the general mood here is very tense.
“The airport staff have been trying to calm everyone down. They’ve been very helpful, but I understand some passengers are very upset.”
