London, Aug. 11 (Reuters): Airlines said flights were returning to normal today but warned of more cancellations and further delays at UK airports after a foiled bomb plot sparked a security alert and stranded thousands of passengers.

UK airport operator BAA Plc said a ban on short-haul flights coming into London’s Heathrow had been lifted and the airport was “busy but calm”.

Most long-haul flights from Heathrow were operating as normal, except for six services to the US, the airline said, but warned of delays at Heathrow and Gatwick airports.

British low-cost carrier EasyJet said it had cancelled about 80 flights today compared with 300 a day earlier and said operations were returning to normal.

Dublin-based Ryanair listed about 30 cancellations from London’s Stansted Airport on its website (www.ryanair.com). The airline cancelled 120 flights yesterday. Virgin Atlantic said it expected to operate its normal flight schedule today but warned of some delays. UK carrier BMI had also resumed its flights.

BAA, which operates Heathrow, Gatwick and Stansted airports, said it had been told the new security measures were in place indefinitely and it had deployed extra staff at airports.