Flights to and from the UK grounded by 'network-wide failure' of air traffic control systems
All flights to and from the UK are reported to be affected.
Reports are emerging of problems with the UK's air traffic control systems.
Passengers on flights from countries all over Europe have been advised of long delays.
This will have a knock-on effect as airports get clogged up with flights that are not authorised to take off.
Passengers have taken to social media, with many saying there is little information available other than that their flight is delayed by several hours.
One user reported being sat on the runway at Budapest airport for a flight to the UK and being told they may be delayed by 12 hours.
Another passenger booked on a flight from Liverpool to Belfast that has been delayed by seven hours. She posted a notice sent to her by Easyjet advising of an "air traffic control issue currently affecting all flights due to fly into or out of United Kingdom airspace."
Airlines have been slow to issue information however Scottish airline Loganair posted on X, formerly known as Twitter: "There has been a network-wide failure of UK air traffic control computer systems this morning.
"Although we are hopeful of being able to operate most intra-Scotland flights on the basis of local coordination and with a minimum of disruption, north-south and international flights maybe subject to delays.
"If you are flying with us today, please check our website for the latest information about your flight before setting off for the airport."
Today is a bank holiday in the UK and one of the busiest days of the year for travel.
This article will be updated.