The spate of empty bomb threats has hit a country on high alert since the Hamas assault on Israel, the ensuing war in Gaza and the fatal stabbing of a teacher in the northern city of Arras last week.

The teenager was arrested yesterday over an emailed bomb threat in Saint-Ouen-l’Aumone, a town northwest of Paris.

Around 1,200 people including around a thousand pupils had been evacuated from the Jean Perrin high school the suspect attended.

No explosives were found following an examination of the site, and the teenager’s exact motive remained unclear.

Interior minister Gerald Darmanin said authorities had made 18 arrests over false bomb threats made yesterday and on Wednesday.

Most of France’s major airports outside Paris were targeted, leading to evacuations, hours-long delays, and dozens of cancelled flights.

Today, France’s justice minister Eric Dupond-Moretti said that 22 probes had been launched in connection with the false alarms.

“There will obviously be convictions, we cannot let this happen,” Dupond-Moretti told broadcaster RTL.

He reiterated his pledge to crack down on “little jokers who have no sense of responsibility.”

“The parents must be there and I remind you that it is the parents who will pay the financial consequences,” added Dupond-Moretti.

Offenders risk two years in prison and a €30,000 fine.

Parisian prosecutor Laure Beccuau warned that the punishment could be even more severe, adding that such bomb threats will now be considered a form of premeditated “psychological violence.”

Speaking to French newspaper Le Parisien, Beccuau said that such an offence is punishable by three years in prison and a €45,000 fine.

“Minors will be brought before a juvenile judge,” added Beccuau.