The hoaxes involved flights from Greece to Britain, but particularly targeted low-cost carriers and flights to or from Bulgaria, Czech Republic and Italy.
Three flights were diverted but all the jets landed safely with no explosives found.
No claim of responsibility was made for all the flights, but a threat against two flights sent to airports in Rome and published by an Italian newspaper contained misogynistic messages.
Under escort, diversions
At least five flights received an air force escort after receiving bomb threats.
Bulgaria’s air force escorted three Ryanair planes headed for Sofia from Madrid, Copenhagen, and London Stansted. All three planes were inspected and no explosives found, an interior ministry spokesperson told AFP.
French fighters accompanied an Aer Lingus flight from Dublin that was headed to Rome, diverting it to the Evreux military base 100 kilometers (60 miles) west of Paris.
Other jets were also diverted.
The Ryanair flight from London-Stansted to Sofia was diverted to Plovdiv Airport, east of the capital, while a Wizz Air flight from Milan to Warsaw was re-routed to Vienna, the airlines said.
Who and why?
Italian newspaper Il Corriere della Sera published the text of a message sent to ADR, the company that manages Rome’s airports. A company source confirmed the report to AFP.
“You are all accomplices in a criminal conspiracy, and for this we want to annihilate you. Right now explosive devices have been placed on the following flights: AY1751 Helsinki–Rome and EI402 Dublin–Rome,” read the message, with media noting it was written in “broken Italian”.
“We Male State fighters with our actions today will leave a mark in history. Your feminist regime will remember it forever. The explosion will occur in 60 minutes. Today your sky will be red,” read the text.
There is a far-right movement in Russia called the Male State, but AFP could not confirm any link to the message.
Prague Airport spokeswoman Denisa Hejtmankova told AFP the airport had received threats in emails from anonymous addresses.
The EU’s transport commissioner, Apostolos Tzitzikostas, wrote on X that it was “too early to draw conclusions on whether the reported incidents are linked.”
But European authorities say there has been rise in hybrid attacks, sometimes linked to Russia or Iran.
Landing safely
Most of the flights targeted Thursday landed without incident at their original destinations.
Those included a Lot Polish Airlines flight from Warsaw to Brussels and a Wizz Air flight from Milan to Bucharest.
In the Czech Republic, four targeted planes bound for Prague flown by Ryanair, Easy Jet and Sky Express all landed safely.
“We perceive the credibility of the threats as low,” said Czech police on X. “Nevertheless, we are not underestimating the situation, and all necessary security measures have been activated.”
Danish police said two threatened planes landed in Copenhagen as scheduled. “Our assessment is that there is no danger, and there has never been any danger, to passengers or anyone else at the airport,” Copenhagen police told AFP.
In Greece, Aegean Airlines said its flights from from Thessaloniki to Milan and from Athens to Vienna, had received “unfounded” threats.
Threats were directed at three flights linked to Madrid, although Spanish airport operator Aena declined to name the airlines nor give other details on the flights. It was not immediately clear whether the three flights included Ryanair’s Madrid-Sofia flight.
Concerned travellers
Travellers at Rome’s Fiumicino Airport expressed mixed feelings over the threats.
“It’s very concerning, we’re very concerned about the security in Europe in general, so it’s very fearful to be here,” Brazilian Natalia Lobo, 29, told AFP.
French traveler Ella Germain, 20, said the news reports had only created “a little bit of worry”.
The flights represented a tiny percentage of Europe’s air traffic on Thursday. Some 25,072 flights were scheduled across the continent, according to Eurocontrol, the continent’s aviation safety body.
Earlier threats
On Tuesday, 10 flights were targeted with bomb threats. All turned out to be hoaxes.
The alerts forced the closure of one Warsaw airport and the deployment of Italian air force jets to protect flights.
On Monday, a Wizz Air flight from London’s Luton airport to Sofia was diverted due a bomb threat and made an emergency stop in Budapest.
