Polish Prime Minister Mateusz Morawiecki branded as an "act of state terrorism" the arrest Sunday of Belarusian opposition activist Roman Protasevich after his flight was diverted and forced to land in Minsk. Morawiecki also said on Twitter that he had asked European Council chief Charles Michel for EU discussions Monday on "immediate sanctions" against Belarus, adding that the arrest "cannot go unpunished". "I condemn in the strongest terms the detention of Roman Protasevich by Belarusian authorities, after a Ryanair passenger aircraft was hijacked. This is a reprehensible act of state terrorism," he said. The charge d'affaires of the Belarusian embassy in Warsaw has been summoned to the foreign ministry for an explanation, the TVN24 channel reported. Poland is highly critical of Belarusian President Alexander Lukashenko and with Lithuania has taken a leading role in Europe in calling for increased sanctions following a bloody crackdown on protests. Former European Council chief Donald Tusk, also a former Polish prime minister, wrote on Twitter Sunday that Lukashenko "has become a threat not only to his own citizens but also to international security". He called for "an immediate and tough reaction of all European governments and institutions". dt/jj