Ryanair CEO Calls Belarus Flight Diversion ‘Premeditated Hijacking’

On Sunday, Belarus scrambled a jet fighter to intercept a Ryanair commercial jet flying over the country en route from Athens to Vilnius, Lithuania. Belarus says it diverted the plane because of a suspected bomb aboard. While on the ground in Minsk, authorities arrested a prominent dissident living in exile who was a passenger, along with his girlfriend.

The European Union and the U.S. have called the incident a brazen case of interference with civilian aviation. The EU has urged its carriers not to fly over Belarus. Belarus said it acted responsibly and in accordance with international protocols for dealing with a bomb threat.

On Thursday, foreign ministers of the Group of Seven industrialized nations and the EU’s foreign policy chief called the diversion “a serious attack on the rules governing civil aviation” and called on the United Nations’ International Civil Aviation Organization to investigate the incident.

The ICAO later said it would do so, and ICAO Council President Salvatore Sciacchitano said the event “posed apparent and serious threats to the legal framework” governing commercial aviation.

Mr. O’Leary, in his letter, said Belarus had made false and inaccurate claims in its accounting of what happened and called Minsk airport officials “obstructionist.”

He called on the government to release the arrested dissident, Roman Protasevich, and his partner and to identify three other passengers who left the plane in Minsk. He wrote that Ryanair believes they are state security agents “operating at the behest of your Government to arrange for the unlawful hijack of our aircraft.”

Belarus has put forward a sometimes-changing version of events that European leaders have called not credible. It published an email it said it received from Hamas, the militant group that rules the Gaza Strip, warning of a bomb aboard the aircraft. Hamas has denied involvement.

The company that operates the encrypted server through which the email was sent said Thursday it was delivered after the plane was diverted.

Belarus President Alexander Lukashenko has also said the country received a warning from Switzerland about a bomb threat on the plane. Switzerland has said it had no knowledge of such a threat and hadn’t been in contact with Belarus about the matter. Mr. Lukashenko’s office and the country’s aviation department didn’t immediately respond to requests for comment on Mr. O’Leary’s letter or the timing of the bomb-threat email.

In Mr. O’Leary’s account, the pilot in command of Ryanair flight 4978 was left no choice but to divert away from Vilnius and land in Minsk based on information given by the local air-traffic controller, who was communicating with the plane while it was in Belarus airspace.

In a transcript released by Belarus of part of the conversation between the plane’s pilots and ground control, Ryanair pilots asked several times for traffic controllers to confirm the veracity of the threat and their recommendation that the plane turn around and land in Minsk.

Ryanair has declined to provide details about the incident.

The letter claims controllers refused to contact Ryanair when requested by the pilot-in-command, after he had been alerted to the bomb threat. Mr. O’Leary accused Belarus of falsely claiming in its account of events that the country’s aviation officials had attempted to contact the airline’s central operations.

He complained about the treatment of passengers and crew and said ground staff at Minsk hindered the aircraft’s ability to return quickly to the air. After landing, crew and passengers were escorted by armed guards and then detained for “over 6 hours without explanation,” Mr. O’Leary wrote. The airport then failed to provide an English interpreter, leaving crew unable to communicate with handling staff until Ryanair was able to provide a Russian translator by telephone.

Sniffer dogs were used to inspect passengers’ baggage, but the luggage wasn’t put through the standard procedure of being X-rayed before being placed back on the aircraft, Mr. O’Leary charged. He said airport staff refused to refuel the aircraft and then refused to accept credit-card payment for the fuel. Later, he wrote, staff refused to allow passengers to reboard when the jet was ready to take off.

—Max Colchester and Georgi Kantchev contributed to this article.

Write to Benjamin Katz at [email protected] and Daniel Michaels at [email protected]