Belarus President Alexander Lukashenko is said to have personally ordered the passenger plane, which took off from Athens on Sunday morning with final destination Vilnius, Lithuania, to make an emergency landing in the capital Minsk.

On board the plane was 26-year-old Roman Protasevich, former head of the opposition channel Nexta on Telegram, who, like other prominent opposition figures, is living in exile.

He was then arrested at the airport.

"Completely unacceptable"

Foreign Minister Ann Linde reacted quickly to the information in a post on Twitter, and says in a written comment to SVT Nyheter that what happened is "deeply worrying and outrageous".

- The Belarusian action is completely unacceptable and has exposed all passengers on the plane to significant safety risks, she says.

- Of course, we also demand that Roman Protasevich should be released immediately.

The arrest is another example of the regime's attempts to silence free speech.

Sweden will continue its strong support for independent media and freedom of expression.

Will discuss consequences

According to the Foreign Minister, the Swedish Embassy in Minsk is now working to get more information about what happened.

The embassy will not receive information that Swedish citizens have been on board.

Tomorrow, Monday, the European Council will meet. Ann Linde also states that she will "discuss possible consequences" with her EU colleagues.