Belarus forced an Athens-to-Vilnius Ryanair flight carrying a wanted opposition activist to divert and land in Belarus on Sunday, provoking a furious outcry from European leaders.

Belarusian state television reported that Roman Protasevich, a 26-year-old opposition blogger exiled in Poland, had been detained in Minsk after flight FR4978 was diverted from EU airspace — ostensibly over a security scare.

Poland’s Prime Minister Mateusz Morawiecki denounced Belarus’ diversion of the flight as “an act of state terrorism”, while French Foreign Minister Jean-Yves Le Drian called for a “strong and united response” from the European Union.

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The EU will discuss possible sanctions over the major diplomatic incident at a summit on Monday and Tuesday, a spokesman said.

After hours grounded in Belarus, the flight was able to continue on its journey, landing in Vilnius at 1825 GMT, the airport’s online arrivals board said.

Officials had yet to confirm whether Protasevich was onboard or had remained in detention in Belarus.

Minsk’s airport had released a statement earlier saying that the aircraft had to make an emergency landing there at 1215 GMT following a bomb scare.

“The plane was checked, no bomb was found and all passengers were sent for another security search,” said Nexta, a Belarus opposition channel on the Telegram messaging app, which Protasevich previously edited.

The Telegram channel of Lukashenko’s press service said the president had given the order to divert the flight. It added that he had also ordered a Mig-29 fighter jet to accompany the aircraft.

The incident comes as Belarus authorities intensify their crackdown on the opposition following historic protests that gripped the ex-Soviet country after last year’s disputed presidential election.

The diversion of a flight between two EU countries to Belarus, and the arrest of an opposition activist who had been onboard, prompted a torrent of outrage from European leaders.

“We hold the government of Belarus responsible for the security of all passengers and the aircraft,” EU foreign policy chief Josep Borrell tweeted earlier.

“ALL passengers must be able to continue their travel immediately,” he said, implicitly demanding Protasevich’s release.

Lithuanian President Gitanas Nauseda described the incident as “unprecedented” and blamed the Belarus regime for the “abhorrent action”.

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In Greece, where the flight started its journey, Prime Minister Kyriakos Mitsotakis tweeted: “The forced landing of a commercial plane to detain a journalist is an unprecedented, shocking act.

“We demand all passengers’ immediate release,” he added, calling for EU action to “step up pressure on Belarus. Enough is enough”.

The government in Ireland, where Ryanair is headquartered, described the incident as “absolutely unacceptable”, while NATO called it “dangerous” and demanded an international investigation.

Since last August’s disputed election, Belarusians have taken to the streets demanding the resignation of Lukashenko, who has ruled for over two decades.

In 2020, Protasevich and Nexta founder Stepan Putilo, 22, were added to Belarus’s list of “individuals involved in terrorist activity”.

The two bloggers — both now based in Poland — were added to the list based on earlier charges of causing mass unrest, an offence that can lead to up to 15 years in jail.

Belarus had also labelled the Nexta Telegram channels and its logo “extremist” and ordered them blocked.

Nexta Live and its sister channel Nexta — with close to two million subscribers on Telegram — are prominent voices of the Belarus opposition and helped mobilise protesters.

“It is absolutely obvious that this is an operation of secret services to capture the plane in order to detain activist and blogger Roman Protasevich,” exiled opposition leader Svetlana Tikhanovskaya said on Telegram.

The opposition says that Tikhanovskaya, who fled to neighbouring Lithuania after the election, was the true winner of last year’s presidential vote.

A member of the Nexta team, Tadeusz Giczan, said on Twitter that representatives of the Belarusian security agency had been on the flight with Protasevich.

“Then when the plane had entered Belarus airspace, the KGB officers initiated a fight with the Ryanair crew insisting there’s an IED onboard,” he said.

A spokeswoman for state company Lithuanian Airports, Lina Beisine, told AFP that Minsk airport had said the flight was redirected “due to a conflict between a member of the crew and the passengers”.

Ryanair said the flight’s crew had been notified by Belarus air traffic control of “a potential security threat on board” and were instructed to divert to Minsk, the “nearest” airport.

Lithuanian Foreign Minister Gabrielius Landsbergis said there were 171 passengers aboard the flight, most of them Lithuanian nationals.

The EU and the United States have sanctioned Lukashenko and dozens of officials and businessmen tied to his regime with asset freezes and visa bans.

The opposition protests in Belarus, which left at least four people dead, have now subsided, but journalists and activists continue to receive prison sentences in the aftermath.