Air travel to and from Britain has been plunged into chaos in the wake of the discovery of a plot to blow up airlines on transatlantic flights. Many airlines said they were cancelling all flights to Britain and to the epicentre of the threat, London Heathrow, one of the world's busiest airports.
The inter-connected nature of international air travel meant that the disruption was rippling out across the world.
British anti-terrorist police said the plot involved explosives concealed in hand luggage, which led to security being beefed up in most of Britain's airports, a measure which was causing delays.
British Airways said it was stopping all inbound and outbound short-haul European flights from Heathrow, its hub, until 1400 GMT.
"British Airways, along with all other airlines, is experiencing major disruption to its operations at London Heathrow... because of the severe airport congestion, following the introduction of new security arrangements," the airline said.
Lufthansa of Germany said it was pulling all flights to Britain until 1500 GMT while Spain's Iberia said none of its flights to Heathrow would take off until 1200 GMT.
Alitalia grounded all flights to Britain and aviation authorities in the Netherlands said they were cancelling all flights to Heathrow until at least 1500 GMT.
French airline Air France said it had cancelled its three morning flights from Paris to London due to over-saturation at London Heathrow airport and was to review the situation at 1200 GMT.
Six British-bound flights from the Mediterranean city of Nice -- four operated by British Airways and two by the low-cost carrier Easyjet -- were also cancelled, leaving hundreds of passengers stranded, the airport said.
Turkish Airways said it was scrapping all of its flights to Heathrow and Greek carrier Olympic Airlines advised passengers travelling to Britain to expect cancellations.
Airports in Denmark and Sweden also increased security and suspended flights to London.
In Asia, airlines said they were waiting for further information and that it was highly possible they would have to cancel flights to Britain.
A spokeswoman for Japan's All Nippon Airlines said a flight which left from Tokyo for Heathrow at 0240 GMT might have to land at a different airport.
Japan Airlines, Asia's largest airline, said two flights to Heathrow took off -- one from Tokyo and the other from Osaka.
Thai Airways said one of its flights took off for Heathrow around 0500 GMT.
Other flights to London were to leave Bangkok around 1700 GMT and so far none had been delayed or cancelled, a spokesman said.
Airport officials and travel agents in China reported no cancellations or delays of flights although Hong Kong's flag carrier Cathay Pacific warned of delays going to London but said there were no plans to cancel any of its four daily flights.
African airlines were also affected.
A spokesman for Kenya Airways said it would comply with requests from the British authorities to introduce new restrictions on hand luggage.
"We are putting in security plans starting today. At this point in time it will be on all flights out of London. We are still going through the plans but no hand luggage will be allowed into flights out of London," said Michael Okwiri, a London-based spokesman for the airline.
