More than 14 European flights were targeted by hoax bomb threats on Thursday, prompting fighter jets from Italy, France and Bulgaria to scramble and escort aircraft, as authorities across Europe investigated a third consecutive day of security alerts.
The European Union said it was not yet clear whether the incidents were connected, adding that it was monitoring developments closely in coordination with national authorities.
"Any threats against civilians are unacceptable," EU Transport Commissioner Apostolos Tzitzikostas said in a post on X, adding that it was "too early to draw conclusions on whether the reported incidents are linked".
More than 20 hoax bomb threats have been reported against European flights this week, with low-cost carriers particularly affected. Flights to and from Bulgaria, the Czech Republic and Italy were among those targeted.
Three aircraft were diverted on Thursday, but all landed safely and subsequent inspections found no explosives.
Ryanair, Finnair and other airlines targeted
Ryanair was among the airlines most affected, with at least seven reported incidents this week.
Three of its aircraft travelling to Sofia from Madrid, Copenhagen and London Stansted received bomb threats, according to a spokesperson for Bulgaria's Ministry of Transport.
Two aircraft landed in Sofia, while the flight from London Stansted was diverted to Plovdiv Airport. Bulgarian fighter jets escorted all three planes, with the country's Defence Ministry saying such missions are intended to detect, identify and escort aircraft.
All three aircraft were subsequently inspected, with no explosives found, an Interior Ministry spokesperson told AFP.
A Finnair flight from Helsinki to Rome was also escorted by an Italian Air Force fighter jet and checked by bomb experts after a threat was reported.
The aircraft landed safely at Rome Fiumicino Airport, where a spokesperson confirmed that no explosives had been found. Finnair spokesperson Stiina Tuunanen said the airline followed established procedures and worked closely with local authorities.
Another Finnair flight, from Helsinki to Vienna, was also reportedly targeted by a false bomb threat.
Flights diverted across Europe
Other airlines affected included Wizz Air and Aer Lingus.
A Wizz Air flight from Milan to Warsaw was diverted to Vienna following a threat, while another flight travelling from Milan to Bucharest landed safely. Romanian authorities said a crisis unit was subsequently established at Henri Coanda Airport.
An Aer Lingus flight from Dublin to Rome was also diverted to France following a bomb threat. French authorities said military aircraft escorted it to the Évreux air base, west of Paris.
The airline confirmed that the aircraft landed safely and said it would work to arrange alternative travel for passengers to their final destination.
Four Prague-bound aircraft operated by Ryanair, easyJet and Sky Express were also targeted.
Czech police said they considered the threats to have low credibility but had activated all necessary security measures. Prague Airport spokesperson Denisa Hejtmankova said the threats had been received through emails sent from anonymous addresses.
Meanwhile, two aircraft arriving in Copenhagen were also targeted. Danish police said their assessment was that there had been no danger to passengers or anyone else at the airport.
Authorities investigate origin of threats
The origin and motives behind the threats remain unknown, although the incidents come amid growing concerns over hybrid attacks across Europe.
Hybrid threats can include a range of activities, such as sabotage, cyberattacks, drone incidents, espionage and disinformation. European authorities have previously linked some such activity to Russia and Iran.
France's Secretary-General for Defence and National Security, Nicolas Roche, highlighted the increasing number of such incidents during an address to parliament last month, referring to a growing concentration of hybrid attacks across Europe.
The latest wave of aviation threats follows similar incidents earlier in the week.
On Tuesday, 10 flights were targeted by bomb threats, all of which were subsequently found to be hoaxes. The alerts prompted the closure of an airport in Warsaw and the deployment of Italian fighter jets to escort aircraft.
On Monday, a Wizz Air flight travelling from London's Luton Airport to Sofia was diverted to Budapest following a bomb threat, forcing it to make an emergency landing.
The EU said it would continue to follow developments in close coordination with national authorities as investigations into the incidents continue.
