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

European leaders reacted furiously after the incident, which led to the arrest of Belarusian opposition activist Roman Protasevich, and which Poland’s Prime Minister Mateusz Morawiecki denounced as “an act of state terrorism”.

Several European leaders called for talks Monday on fresh sanctions against Belarus.

Earlier Sunday, the opposition Telegram channel Nexta said Protasevich, its former editor, was being held in Minsk after his flight had been forced to land on the orders of Belarusian President Alexander Lukashenko.

A statement from Minsk airport said the aircraft had had to make an emergency landing following a bomb scare.

“The plane was checked, no bomb was found and all passengers were sent for another security search,” Nexta said. “Among them was… Nexta journalist Roman Protasevich. He was detained.”

The Belarusian interior ministry initially confirmed the detention on Telegram, but the post was later deleted.

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

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

‘Abhorrent action’

The European Union’s foreign policy chief Josep Borrell tweeted: “We hold the government of Belarus responsable for the security of all passengers and the aircraft.

“ALL passengers must be able to continue their travel immediately,” he said, implicitly demanding the release of exiled opposition activist Roman Protasevich.

Gitanas Nauseda, the president of Lithuania, where the flight was bound, called the incident an “unprecedented event” and blamed the Belarus regime for the “abhorrent action”.

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”.

Polish Prime Minister Mateusz Morawiecki condemned Protasevich’s arrest and called the forced landing an “act of state terrorism”. Protasevich lives in exile in Poland.

French Foreign Minister Jean-Yves Le Drian also condemned the incident, calling for a “strong and united response” from the European Union.

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