British Airways and Air France have scrapped five U.S.-bound flights on Sunday and Monday amid fears of airborne terrorist attacks.

The move came after U.S. officials cited new intelligence that Osama bin Laden’s al Qaeda network may be targeting five or six U.S.-bound flights from Europe. U.S. security officials said they alerted the countries and airlines involved and it was up to them whether to cancel the flights or step up security.

British Airways said it had cancelled flight BA223 to Washington on Sunday and Monday, and the return BA222 flights to London on the same days. Sunday's BA207 London to Miami flight was also cancelled. Sunday's BA207 London to Miami flight was also cancelled. "We cancelled these flights on advice from the UK government for security reasons," a spokeswoman for the airline told Reuters.

Air France scrapped two Paris-Washington flights. "We confirm that for reasons of safety we have cancelled flight number 026 to Washington on February 1 and the same flight on February 2," an Air France spokeswoman said.

French Foreign Minister Dominique de Villepin told France's TF1 TV station: "We have been for several months in an extremely tense international environment...Air France has thus decided to take necessary measures and suspend the flights, I think it's a wise decision."

On Sunday, American airline, Continental became the latest to cancel flights. It scrapped Sunday's flight from Glasgow in Scotland to Newark.

U.S. officials fear resurgent al Qaeda attacks

Though the exact nature of the latest U.S. intelligence remains unclear, a spokesman for the U.S. Department of Homeland Security told the BBC, "we remain concerned about al Qaeda’s desire to target international aviation." He added: "There was specific credible threat information that was shared with some foreign governments, including the British and French Governments, and the decisions were made to cancel these flights."

U.S. Homeland Security Secretary Tom Ridge has said the U.S. government consistently receives intelligence that al Qaeda is still interested in using aircraft, particularly commercial airplanes, to carry out an attack.

Al Qaeda has been blamed for carrying out the Sep.11, 2001 terrorist attacks, involving four hijacked commercial airplanes in New York and Washington, which killed more than 3,000 people.

Debate over use of sky marshals

The latest disruption in transatlantic air traffic, which has caused major inconvenience to hundreds of irate passengers, is expected to once again stir the debate over the use of armed guards on flights, a key demand by the U.S. in enhancing air security.

The issue arose after Washington raised its terror-alert in December to the second-highest level and asked British Airways and Air France to cancel several U.S.-bound flights and put armed marshals on flights.

However several European countries including Sweden, Denmark and Portugal have opposed the new regulations. France and Britain have indicated they might comply in case of a heightened security threat.

"New threats like those that we experienced at the end of last year, we take these threats seriously and you need within the framework of terrorism prevention to be meticulous, very vigilant in liaison with airlines, that is Air France and British Airways," French Foreign Minister Villepin said.