Experts say perfect security is elusive at all airports

Security agents at the main airport in Paris are trained to detect all manner of increasingly sophisticated devices that could doom a flight.

Airport authorities in France and elsewhere are painfully aware of the risks, but hesitant to speculate as to whether an airport security lapse could have contributed to Thursday's crash of EgyptAir Flight 804.

Security is being further reinforced ahead of the French Open tennis tournament, which starts Sunday, and the Euro 2016 soccer championships, a monthlong tournament that begins June 10.

The March 22 attacks that killed 32 people in Brussels, at the airport and in a metro station, add to the sense that public places like airports are vulnerable.

French investigators are doing background checks and interviewing ground staff at Charles de Gaulle who had a direct or indirect link to Flight 804, from baggage handlers to gate agents, a judicial official said, speaking on condition of anonymity because he was not authorized to speak publicly on the probe.

Since the January 2015 Charlie Hebdo newsroom massacre in Paris, French authorities withdrew or refused 85 red badges, according to Paris Aeroports, nearly 70 of them taken away within a month after last November's attacks.

The badges are awarded by the deputy prefect for airports, a state representative, after a training course and an exam, plus security checks by police.