Airlines cancelled almost one-third of flights from Britain's busiest airport on Sunday, plunging travellers into a fourth day of travel chaos triggered by a thwarted alleged bomb plot aboard a flight.
British Airways said it had scrapped 30 per cent of flights from London's Heathrow Airport on the instructions of airport operator, the British Airports Authority (BAA).
The airport operator said 70 per cent of flights on all airlines at Heathrow were expected to operate, but warned that tough new screening measures for passengers and luggage meant delays were inevitable.
BAA's chief executive for Heathrow, Tony Douglas, said the airport was doing its best, but that delays "will go on until the security threat level is reduced."
On Sunday, British Airways cancelled almost 100 flights to Europe from Heathrow and scrapped all its domestic flights from London's second airport, Gatwick. Most long-haul flights were operating, although 10 BA services to the United States were cancelled.
Scores of flights from Britain to Europe and the United States were also cancelled on Saturday. Passengers were delayed so long by strict new security measures that many missed their flights.
British Airways said in a statement that it "cannot rule out the possibility that flights will once again depart without all their passengers because of ongoing problems with BAA's security search process and baggage operation at Heathrow Airport.