Belarusian President Alexander Lukashenko ordered a Ryanair (RYA.I) flight from Greece to Lithuania to land on Sunday in Minsk, where a Belarusian opposition activist on board was detained, prompting international condemnation.

EU member Lithuania urged the European Union and NATO to respond, Germany called for an immediate explanation and Poland's prime minister called it a "reprehensible act of state terrorism".

The head of the European Commission, Ursula von der Leyen, said Belarus's action was "utterly unacceptable".

The aircraft, flying from Athens to Vilnius, had almost reached Lithuania when it changed direction and was escorted to Minsk, the Belarusian capital, after reports that it had explosives on board, according to an online flight tracker and BelTA state news agency.

Belarusian law enforcers took activist Roman Protasevich, 26 from the plane and detained him. He was placed on a wanted list after street protests last year following a presidential election in which Lukashenko was declared the winner but opponents complained of electoral fraud.