By Ido Vock
At least 18 people have been arrested after a wave of hoax bomb threats prompted evacuations across France.
The Palace of Versailles, the Louvre, as well as schools, airports and hospitals have all been targeted.
Those behind the disruption are mostly minors, authorities say.
The threats come at a time of heightened tension in France, after a teacher was fatally stabbed by an alleged jihadist last week at a school in the northern city of Arras.
Fifteen regional airports had threats made against them on Friday, from Biarritz, Bordeaux, Nice and Toulouse in the south to Lille and Brest in the north. Airports have been evacuated on several days this week, causing the cancellation of at least 130 flights.
Tourist sites have also been targeted. The Palace of Versailles was closed for the fifth time in a week on Friday after yet another threat, affecting thousands of visitors.
Mayor François de Mazières appealed for the “idiocy” to stop, telling Franceinfo that 10,000-15,000 people visited France’s former royal residence every day and warned the hoaxes “could have consequences for attendance”.
The Louvre in Paris was also forced to evacuate thousands of visitors last Saturday.
Twenty-two investigations have been launched, Justice Minister Éric Dupond-Moretti told RTL radio on Friday, but the arrests appeared to have no effect on the spate of scares.
France was placed on its highest state of counter-terrorism alert last week following the killing of 57-year-old teacher Dominique Bernard. The suspect, a former pupil at the Gambetta high school in Arras, is a Russian national of Chechen origin.
On Friday, a high school in Grenoble in the south-east was evacuated for the second time in two days, and students and staff were also forced to leave a high school in Bourg-en-Bresse in the east.
Earlier this week, pupils in one Toulouse school were told to go under their tables when a suspect package was spotted in front of the building.
Authorities have arrested several students they suspect of being behind the scares.
A 16-year-old was arrested on Thursday a few hours after his school in Val-d’Oise, north of Paris, was evacuated. Another student suspected of calling in a hoax threat was arrested a few hours after 1,200 pupils had to leave their school premises.
Interior Minister Gérald Darmanin said on Thursday night that 18 people, mainly minors, had been arrested in a space of 48 hours but he stressed that France was under no specific threat.
The threats have been made by phone or email, via a website launched in 2020 to text police officers direct, and by contacting official police social media accounts.
Mr Dupond-Moretti warned those he called “little jokers” that they would be “found and punished”.
Authorities are using IP addresses and phone numbers to identify those responsible. Calling in a fake bomb threat is a crime in France that carries up to three years in prison and a €45,000 (£39,000) fine.