[2] On 23 May 2021, Ryanair Flight 4978 (Athens–Vilnius),[3] operated by the Polish subsidiary Buzz,[4] a Boeing 737-800 carrying six crew members and 126 passengers,[5] was diverted to Minsk National Airport after ground authorities reported a bomb on board, whilst the aircraft was 45 nautical miles (83 km; 52 mi) south of Vilnius and 90 nautical miles (170 km; 100 mi) west of Minsk, but still in Belarusian airspace.

[6][5][7] The Department of Aviation of Belarus claimed that an email was received in the generic mailbox info@airport.by containing the following text at 09:25 UTC (12:25 local):[8] "We, Hamas soldiers, demand that Israel cease fire in the Gaza Strip.

[13][14] According to Ryanair CEO Michael O'Leary, the pilots were told by Belarusian ATC that there was a bomb on board which would be detonated if the aircraft entered Lithuanian airspace, hence the need to divert to Minsk.

Opposition leader Pavel Latushko claimed that Belarusian ATC threatened to shoot down the passenger plane if it did not make an emergency landing in Minsk.

[34] Additionally, Tadeusz Giczan, a member of the Nexta Telegram channel, which was previously edited by Protasevich, said that officers of the KGB had been on the flight and had "initiated a fight with the Ryanair crew", insisting that there was a bomb on board the aircraft.

[5] Passengers noted having to wait 2.5 hours without water, toilet breaks or phone calls, while 50 to 60 Belarusian security officers at Minsk airport carried out a search that included checking the belly of the aircraft for bombs.

[41][42] On 24 May 2021, the director of the Department of Aviation of the Ministry of Transport of Belarus, Artyom Sikorsky, read out an e-mail letter, which they said was sent to Minsk airport on 23 May.

[51] According to The Wall Street Journal, Ryanair CEO Michael O'Leary rejected the version of events made by Belarusian government officials and called the situation a "premeditated hijacking".

[71] Belaeronavigatsia, the Belarusian state-owned enterprise responsible for regulating airspace and providing air traffic control in Belarus, was sanctioned by the EU.

[73][74][75] In November 2021, ICAO announced that the investigation report had been delayed until January 2022, due to the "volume of data submitted and additional state clarifications still being required".

Access to the controller of the Ryanair flight or to the call records of officials, as well as footage from well-placed airport cameras were also not provided to the investigation team.

[80] On 28 May 2021, Kremlin spokesman Dmitry Peskov asserted that "the problems were purely technical in nature, and that the issue should not become an additional irritant in Russia's relations with the European Union".

[81] On 1 June, Lufthansa was forced to cancel flights to Moscow because authorisations were not received on time, prompting the German government to retaliate by denying Russian airlines access to its airspace.

[82] On 23 May 2021, the Lithuanian public prosecutor's office opened a pre-trial investigation under the Criminal Code articles of "Hijacking an Aircraft" and "Treatment of Persons Prohibited under International Law".

[15] Since there were four Americans on board the plane, the FBI investigated the incident, and on 20 January 2022, the United States Attorney for the Southern District of New York charged four Belarusian officials with conspiracy to commit aircraft piracy.

According to a court statement, the charges stem from their actions in providing the flight crew with false information about an alleged explosive device on board, which led to the unlawful deprivation of liberty of 132 passengers, including Polish citizens.

[87][88][89] The act was denounced by the United States, United Kingdom, European Union, NATO, and some civil aviation authorities as an act of air piracy and state terrorism; a violation of international law, including the Convention on International Civil Aviation; and an infringement of basic human rights by an authoritarian regime.

[90][91][92][62][93][94] European Commission president Ursula von der Leyen described the incident as "utterly unacceptable", stating that "any violation of international air transport rules must bear consequences".

[123] Reuters reported that Turkey "insisted that any mention of support for more Western sanctions on Belarus, and calls for the release of political prisoners there, would be left out" of the text published on the NATO website.

[128] United Nations Secretary-General António Guterres stated that he was "deeply concerned" over the apparent forced landing and subsequent detention of Roman Protasevich and asked for a full investigation into the incident.

He noted that if a fake bomb threat had been made, a crime would have been committed under Article 1 of the Convention for the Suppression of Unlawful Acts against the Safety of Civil Aviation and Belarus should "facilitate the continuation of the journey of the passengers and crew".

[130] Ukrainian aviation lawyer Andriy Huk suggested that the interception by the military aircraft and redirection of the airliner to a more distant airport could have jeopardized the safety of the passengers and crew.

[132] Using the same two treaties as a basis, aviation lawyers with the international firm DLA Piper questioned the legality of the events and raised two possible ways that aircraft safety may have been jeopardized.

The first is the burden of additional work required by the crew to land safely at an unfamiliar airport, which was further complicated by warnings of an on-board bomb and the presence of a military escort.

The same experts also clarify that the aircraft, crew, and passengers were in an area of Belarusian sovereignty and subject to the country's laws while flying above it according to Article 1 of the Chicago Convention.

[60] Scandinavian Airlines (SAS) announced that in line with instructions from the Swedish Transport Agency, the twice-weekly flight between Oslo and Kyiv would be rerouted to avoid Belarusian airspace.

[136] Singapore Airlines (SIA) also began rerouting flights bound for Europe to avoid Belarusian airspace from 25 May, citing safety concerns.

[15] Bucharest's Sector 1 mayor Clotilde Armand, following calls from historian Andrei Oișteanu, began preparations to rename the street where the Belarusian embassy is located in Romania to Roman Protasevich Street, citing that the consequence of this gesture of support for the detained journalist would imply that "all correspondence to and from the embassy would bear the dissident journalist's name and all Belarusian diplomats would have 'Roman Protasevich' printed on their business cards".

[144] In July 2022, the International Civil Aviation Organization completed a review that condemned the "actions of the Government of Belarus in committing an act of unlawful interference".