Bomb threats divert flights across Europe

French fighter jets escorted an Aer Lingus flight from Dublin to Rome to an airbase in Normandy on Thursday morning, where a bomb patrol was waiting to inspect the aircraft. It was one of at least eight commercial flights hit by bomb threats across Europe, on routes linking Dublin, Madrid, Copenhagen, London, Warsaw, Helsinki and Milan.

The threats against the Rome-bound flights from Dublin and Helsinki arrived in an anonymous email written in Italian, sent early on Thursday to Rome airport's operator ADR and other companies at the airport, Corriere della Sera reports. No official source has confirmed how the remaining threats were delivered. The morning's list by route ran to three Ryanair flights to Sofia from Madrid, Copenhagen and London Stansted — all forced to land in Bulgaria, one at Plovdiv — a LOT flight from Warsaw to Brussels, a Wizz Air flight from Milan Malpensa diverted to Vienna, and Finnair flights from Helsinki to Rome and to Vienna. Four further flights bound for Prague were affected but not yet identified.

Thursday was the third such wave this week. On Monday, a London–Sofia flight made an emergency landing in Budapest under Hungarian fighter escort. On Tuesday, threats against around ten planes, among them an SAS flight from Copenhagen to Warsaw, forced diversions and temporarily closed an airport. No explosives were found on any of them.

Each threat has drawn the same response: fighter escort, emergency landing, bomb squads, hours of inspection. The two planes examined at Copenhagen airport on Thursday were cleared without any suspicious objects being found, according to the Danish news agency Ritzau. Aviation security leaves a carrier no way to test an anonymous email's credibility before reacting; the full apparatus is the only answer available, every time. The Rome-bound threats cost their sender nothing but an email address. The reply consumed fighter sorties over France and Hungary, a military airbase in Normandy taking a scheduled airliner, and bomb squads at Évreux and Copenhagen.

The Guardian's tally by late morning stood at eight planes, with four more flights to Prague still unnamed. Every search completed so far — Tuesday's ten aircraft, Thursday's two at Copenhagen — has ended with nothing found.