Six airports across France were evacuated on Wednesday after emailed "threats of attack", according to news agency AFP, reports Radio France Internationale.
The evacuations at Lille, Lyon, Nantes, Nice, Toulouse and Beauvais airport near Paris will enable authorities to "clear up any doubts" whether the threats are real, the reports say citing an anonymous source.
A spokeswoman for Strasbourg airport in eastern France also said the site was being evacuated after a "threatening email".
Elsewhere, the Palace of Versailles, a major tourist attraction outside Paris, was evacuated for the third time since Saturday for bomb disposal teams to check the site.
France is under a state of "terror emergency," the highest level of the Vigipirate alert and protection system following Hamas's October 7th attack on Israel and Friday's fatal stabbing of a teacher in the northern city of Arras by a man claiming allegiance to the Islamic State group.
A second police source said that Nice, Lyon and Lille airports had resumed normal activity around midday.
A spokesman for France's DGAC aviation authority confirmed evacuations over bomb warnings only at Lille, Lyon, Toulouse and Beauvais, and was unable to give further details immediately. The DGAC's online dashboard showed significant delays at Lille, Lyon and Toulouse.
A post on Nice airport's X (formerly Twitter) account said that "following an abandoned baggage item... a security perimeter was set up to allow the usual checks".
"The situation has now returned to normal," it added.