Airports in Scotland are experiencing delays this morning due to a technical problem that occurred overnight at the Scottish Air Traffic Control Centre, Prestwick.
Edinburgh, Glasgow, Aberdeen and Prestwick airports have been affected due to the issue.
Air traffic controller National Air Traffic Services (Nats) said there was interference on some radio frequencies that are used to speak to aircraft.
"There has been a technical issue overnight at the Scottish Air Traffic Control Centre at Prestwick, the cause has been identified and is currently being resolved. Some impact is expected on flights this morning, but the situation is improving.
"We apologise for the inconvenience people may be experiencing and will update with further details as soon as possible," it said in a statement.
An Aberdeen Airport spokesman said a 'small number' of delays were affecting southbound flights, but would be back to normal as soon as possible.
An Edinburgh Airport spokesman said: "Due to an ongoing issue at the Scottish Airspace control centre there will be a delay to all flights this morning. We are still assessing the situation but customers should expect delays."
The Prestwick centre was opened in 2010, consolidating Nats' four ATC centres to two.
The operations room in Prestwick combines Scottish Area Control Centre (ScACC), Manchester Area Control Centre (MACC) and Oceanic Area Control Centre (OACC).
The ScACC controls aircraft over Scotland, Northern Ireland, Northern England and the North Sea from 2,500ft to 66,000ft.
The MACC controls aircraft over much of the north of England, the Midlands and north Wales from 2,500ft up to 28,500ft, while OACC controls the airspace over the eastern half of the North Atlantic from the Azores (45 degrees north) to a boundary with Iceland (61 degrees north).
Image: Nats' ATC centre. Photo: courtesy of NATS Limited.