Minsk, May 24 (IANS): The whereabouts of dissident Belarusian journalist Roman Protasevich, who was taken into custody after a passenger plane he was on was forced to land in Minsk, remain unknown on Monday.

Protasevich, a 26-year-old blogger and activist who was wanted in his homeland for inciting protests against long-time President Alexander Lukashenko, among other charges, was arrested after his Ryanair flight from Greece to Lithuania made an emergency landing on Sunday, reports dpa news agency.

His father, Dmitry, said in an interview with Belarusian radio broadcaster Radio Svoboda that he was convinced that the careful operation did "not only involve" the country's secret service.

Russia is a close ally of Belarus.

"The operation was of a large enough scale to spit on the entire international community and their opinion," added the dissident's father, who called the forced landing "an act of terrorism."

"We are very worried about our son," said Dmitry Protasevich.

"Unfortunately, we don't know where he is and how he's doing."

Governments across Europe reacted with outrage, suggesting authoritarian Belarus used the pretext of a safety threat to conduct a "state hijacking" of a civilian airliner to go after a critic.

Belarusian state media reported that the plane's diversion came on Lukashenko's personal instructions, after he had purportedly been alerted to a possible bomb on board.

He also ordered a MiG-29 fighter jet be scrambled to accompany the Ryanair plane, according to the Belta news agency.

Lukashenko, 66, has led Belarus, a former Soviet republic in Eastern Europe bordering EU states Poland, Lithuania and Latvia, for more than a quarter of a century.