Paris - A London-bound British Airways flight was evacuated at Paris's Charles de Gaulle airport on Sunday due to a security scare, but was later cleared for take-off, the airport's operator said. A spokesperson for Aeroports de Paris said an incident "linked to security" had led staff to evacuate the 130 passengers onboard Heathrow-bound flight BA303."There was an incident that led authorities to decide to keep the plane on the ground and to disembark the passengers a few minutes before take-off, to carry out additional checks," the spokesperson said.The checks were completed and the flight was able to take off shortly before noon (10:00 GMT), more than four hours late.British Airways said in a statement: "The safety and security of our customers and crew is always our top priority."We would never operate a flight unless it is safe to do so."Britain has raised its terror threat level to "critical" following the bombing of a London Underground train on Friday that left 30 people injured.