Seven transatlantic flights were cancelled yesterday after American intelligence warned of al-Qa'ida attacks on a number of British Airways and Air France routes.
British Airways has grounded BA223 from London to Washington today and tomorrow, BA222 in the reverse direction on the same days, and today's BA207 from London to Miami.
Two Air France flights between Paris and Washington have also been affected by the security alert.
"We cancelled these flights on advice from the UK Government for security reasons," a spokeswoman for British Airways said.
A US official speaking anonymously said: "We have received threat reporting that indicates al-Qa'ida's desire to target these particular flights."
The intelligence enabled the US authorities to identify flights potentially at risk, but the official said further details were not available. US security officials alerted the countries and airlines involved and it was up to them whether to cancel the flights or step up in-flight security, he said.
In December, Washington raised its terror alert to the second-highest level and asked British Airways and Air France to cancel several US-bound flights, including flight BA223.
US Homeland Security Secretary, Tom Ridge, said the US government consistently receives intelligence that al-Qa'ida is still interested in using aircraft, particularly commercial airplanes, to carry out an attack.
Adding to the jitters on Saturday was a scare on a Virgin Atlantic flight from London to New York, which had to be turned back when a burning smell was detected in the cabin.
The airline said it had probably been due to a technical fault. The plane returned safely to Heathrow.Reuse content