Several flights operated by European airlines faced hoax bomb threats on Tuesday, prompting security searches, diversions and, in one instance, an escort by Italian Air Force fighter jets, officials said.
The affected flights included those operated by LOT Polish Airlines, Scandinavian Airlines (SAS), Wizz Air and Ryanair. The incidents came a day after a flight bound for Bulgaria was diverted to Hungary following a similar bomb threat while airborne. No injuries were reported.
Matthew Borie, co-founder and chief intelligence officer of Osprey Flight Solutions, which advises airlines on security threats, outlined several possible explanations for the incidents, which remain unexplained. These include copycat threats triggered by an initial incident, multiple threats made by an individual or group, or "hybrid warfare" operations carried out by state actors or their supporters.
He said such threats were not new but were occurring amid heightened geopolitical tensions and growing signs of disruption across Europe, including attacks on supermarket refrigeration systems, drone incursions and unexplained alerts on mobile applications.
Borie said Russia could potentially be involved given the focus on Europe, but cautioned that Iranian hybrid warfare was also active in certain parts of the continent.
He urged travellers not to panic, pointing to coordinated response mechanisms adopted by national authorities, including the deployment of NATO fighter jets to escort aircraft when necessary.
Ryanair flights escorted, searched in Italy
A Ryanair flight from Lisbon landed at Rome's Fiumicino Airport on Tuesday morning after an email warning that a bomb was on board, according to an airport official familiar with the incident.
Police bomb disposal experts searched the aircraft, passengers, crew and baggage but found no explosives.
Another Ryanair flight travelling from Dublin to Rome also received a bomb threat, but no explosives were found, the official said, speaking on condition of anonymity as they were not authorised to comment publicly.
The Italian Air Force confirmed that it had scrambled two Eurofighter jets to intercept and escort an aircraft bound for Rome following a report of a suspected threat on a civilian flight from Dublin to Rome Fiumicino.
LOT flight diverted in Poland
In Poland, a morning LOT flight from London's Heathrow Airport to Warsaw's Chopin Airport was diverted to nearby Modlin Airport following a bomb threat, the Polish Press Agency (PAP) reported.
Modlin Airport was temporarily closed during the incident.
LOT said a search of the aircraft found nothing suspicious, while airport authorities later confirmed that normal operations had resumed.
Chopin Airport also received information about a potentially dangerous item aboard an SAS flight arriving from Copenhagen, PAP reported. Standard security procedures were immediately activated, and one of the airport's runways was temporarily closed.
SAS spokesperson Alexandra Lindgren Kaoukji told PAP that passengers had disembarked after the aircraft landed normally and that it was not an emergency landing. The matter was subsequently referred to Polish police.
No explosives found in Spain, Bulgaria
Spanish authorities ruled out the presence of explosives aboard a Ryanair flight from Manchester that landed at Murcia Airport in southern Spain following a bomb threat.
Francisco Lucas, the Spanish government's delegate in the Murcia region, said on X that passengers and crew underwent security checks and the aircraft was inspected.
The flight was carrying 121 people, including crew members, he said.
Meanwhile, Bulgarian authorities found no explosives aboard two aircraft that received bomb threats while heading to Sofia International Airport, Transport Minister Georgi Peev said, according to state news agency BTA.
The planes, which originated in Bergamo, Italy, and Dublin, Ireland, were inspected by counterterrorism officers after landing in Sofia. Neither aircraft was diverted.
Peev said the initial information about one of the threats came from the pilot, who had been informed of the suspected threat through the airline. Bulgarian air traffic control subsequently followed established security protocols to ensure the aircraft landed safely.
On Tuesday, acting Interior Ministry Secretary General Lyubomir Nikolov told reporters that authorities were still working to identify the person who sent the threat.
Wizz Air flight diverted to Hungary a day earlier
The latest incidents followed a bomb threat on Monday involving a Wizz Air flight that departed from Luton Airport near London and was forced to divert to Hungary while airborne.
Hungarian Defence Minister Romulusz Ruszin-Szendi said in a Facebook post that a Gripen fighter jet was scrambled to intercept the aircraft and escort it safely to Budapest's Liszt Ferenc International Airport.
Wizz Air told state news agency MTI that an inspection of the aircraft and its passengers found no threat.
Last month, a flight travelling from Tel Aviv to Vienna also made an emergency landing in Bulgaria following a bomb threat.
Greece investigates threat against cruise ship
Meanwhile, Greek authorities were investigating a bomb threat against the Crown Iris, a Panama-flagged cruise ship operated by an Israeli company, at the port of Syros, an Aegean island.
An initial search conducted on Tuesday by coast guard officers, accompanied by a sniffer dog and a diver, found no suspicious objects. A specialised diving unit was on its way to carry out further inspections, the coast guard said.
The vessel, which had been scheduled to sail to Haifa, Israel, with 940 passengers and 597 crew members aboard, was being evacuated as a precaution.
The presence of the Crown Iris at Greek ports has previously triggered protests, mainly by activists opposing Israel's war in Gaza.