Flights at Gatwick Airport have been suspended due to what it says is an issue in its control tower.
The airport apologised and said it had experienced a problem with its air traffic control systems.
In a statement Gatwick said it was working “to rectify this issue as quickly as possible”.
“Passengers should check with their airline directly or on our website flights page for the latest information on their flight,” the airport added.
Gatwick’s website is showing some flights have been diverted to other airports.