The number of aircraft flying and taking off in southern England has been restricted because of air traffic control computer problems.
Nats, the national air traffic control body, said UK airspace was not shut, nor were all flights in and out of the UK suspended – as one airport had said.
It was working to restore full operations at its Swanwick, Southampton, control centre.
Nats said it “has contingency plans in place to minimise any disruption.”.
“We regret any inconvenience this may cause, however our first priority will always be the safety of the flying public.”
National Air Traffic Control Services provides air traffic navigation services to aircraft flying through UK controlled airspace and at several UK and international airports. Its website said it handled 7,086 flights on Monday. Jersey Airport had tweeted just after 10:00 BST on Tuesday that the computer failure at Swanwick had “resulted in the temporary suspension of all flights in and out of UK air space.”
In an update 25 minutes later, the airport said there was “once again movement in UK skies. However, some delays may result.”
The airport said passengers could check-in as usual.
Flights were also delayed at Nottingham East Midlands Airport and Southampton Airport. Southampton Airport told passengers: “A widespread air traffic control issue is currently affecting all flights to and from Southampton Airport. Air traffic control are currently working to resolve this issue as soon as possible but please check with your airline for the most up-to-date information.”
A spokeswoman for Gatwick Airport said “there are minor delays particularly with flights to Jersey, where the airspace issue is happening.”
She said flights from Europe could be delayed by the restrictions placed around Jersey’s airspace.
Low-cost operator Easyjet said there were no delays or flight problems at present. It flies mainly from Gatwick and Luton.
Heathrow Airport, the UK’s largest hub, said “everything was running fine”, and British Airways said all its flights were operating as scheduled.