Dozens of flights across Europe were targeted by bomb threats this week, triggering emergency responses, flight diversions and aircraft searches as authorities struggled to determine whether the incidents were isolated hoaxes or part of a wider campaign to disrupt the continent.
Although no explosives were found and no injuries were reported, the unusually high number of threats in a short period has raised concerns among security officials, particularly amid growing geopolitical tensions and a series of other suspected acts of disruption across Europe.
The incidents forced some aircraft to change course, make emergency landings or receive military escorts.
Airlines and airport authorities were also required to conduct security checks, although Europe's air traffic authority said the overall impact on aviation operations remained limited.
The threats came against a backdrop of other security concerns, including attacks on supermarket refrigeration systems and unauthorized drone incursions.
Separately, three broadcasters, Ireland's national broadcaster RTE, Britain's Sky and Bulgaria's NOVA TV, received security threats Friday, suggesting that the intimidation campaign may be extending beyond the aviation sector.
The developments have prompted questions about who is behind the incidents, whether they are connected and what their ultimate objective might be.
European security experts are scheduled to meet in Brussels next week to discuss how authorities can better respond to the growing number of hoax threats.
Authorities investigate possible links
No government or organization has been identified as responsible for the airline threats, and authorities have found no evidence establishing a connection to any state actor.
An email containing a bomb threat sent Thursday to airport authorities in Rome and reviewed by The Associated Press (AP) appeared to come from a group describing itself as anti-feminist.
The sender claimed it was targeting what it called a "feminist regime."
A separate European airport received a threat containing similar language, although investigators have not established whether the messages originated from the same sender.
In Amsterdam, Dutch military police detained a man Thursday night at Schiphol Airport in connection with a threat against a flight preparing to depart for Prague, according to Doron Wallin, a spokesperson for the Royal Netherlands Marechaussee.
It remained unclear whether the incident was connected to the wider wave of threats. Wallin said authorities regularly deal with false bomb alerts at airports.
The aircraft eventually continued to Prague later that evening, while the detained man was released the following day.
The uncertainty surrounding the incidents has intensified concerns about possible hybrid warfare, a term used to describe covert and indirect operations intended to destabilize countries without conventional military confrontation.
European authorities have repeatedly warned that Russia could be expanding such activities across the continent. However, they have not attributed the latest aviation threats to Moscow or presented evidence linking them to any government.
Experts consider several possible explanations
Matthew Borie, co-founder and chief intelligence officer of Osprey Flight Solutions, a company that advises airlines on aviation security threats, said several explanations could account for the sudden increase in bomb hoaxes.
The incidents could involve a single threat prompting copycat messages, an individual or group deliberately targeting multiple flights, or a broader operation involving state actors or their supporters.
The concentration of incidents in Europe raises the possibility of Russian involvement, Borie said, but he cautioned against focusing exclusively on Moscow.
"We need to keep in mind, though, that Iranian hybrid warfare is just as active in certain pockets of Europe as well," he said.
Borie urged passengers not to panic, pointing to established response procedures and cooperation among national authorities.
"Don't be alarmed," he said, noting that security agencies have coordinated mechanisms for responding to aviation threats, including the deployment of NATO fighter jets to escort aircraft when necessary.
Jacob Funk Kirkegaard, a senior fellow at the Bruegel think tank in Brussels, said the threats could be testing the ability of European governments, airports and security agencies to respond effectively and coordinate their actions.
He said the apparent objective was to create uncertainty about the reliability of air travel across Europe and undermine confidence in the continent's aviation system.
Even when threats prove false, their consequences can extend beyond individual flights, requiring aircraft inspections, investigations and additional security measures.
Kirkegaard warned that the resulting disruption could have wider economic consequences, with airlines and airports facing mounting costs and operational challenges if the incidents continue.
Cyber threats add to European security concerns
The aviation incidents have coincided with separate threats targeting public figures and media organizations, adding to concerns about the broader security environment.
On Saturday, Italian Foreign Minister Antonio Tajani said his personal information had been published on the dark web, an encrypted part of the internet, leaving him exposed to what he described as "threats and intimidation."
Italian Premier Giorgia Meloni blamed pro-Russian hackers for the disclosure.
Tajani, who also serves as one of Italy's deputy prime ministers, did not specify what personal information had been circulated or identify those responsible. However, he suggested the cyberthreat remained ongoing and reiterated the Italian government's support for Ukraine.
While no connection has been established between the cyberattack, the broadcaster threats and the aviation hoaxes, their timing has added to concerns about the range of security challenges confronting European governments.
For now, investigators face the difficult task of determining whether the bomb threats represent a coordinated campaign, a series of unrelated incidents or a wave of copycat hoaxes.