London's Heathrow Airport is Europe's busiest and is showing delays of over an hour, Saturday morning
Flights are being delayed at Britain's busiest airports because of a technical problem at the country's main air traffic control center.
National Air Traffic Service said it was having a problem switching between nighttime and daytime operations at its control center in Swanwick, southern England.
It said: "This may result in some delays, for which we apologize."
It said technicians were trying to fix the problem.
Heathrow Airport - Europe's busiest - is showing delays of an hour or more on many morning flights Saturday.
London's Stansted airport said departing flights were seeing delays of between 30 minutes and 2 hours because of restrictions on air space and the flow of planes. Gatwick airport said 20 per cent of flights were being delayed.