Belarusian President Alexander Lukashenko had claimed that he had foiled a coup in April last year.
ADVERTISEMENTFive people have been handed lengthy prison sentences in Belarus for an alleged attempted coup last year.
Belarusian President Alexander Lukashenko claimed in April 2021 that he had foiled a coup and "assassination" attempt planned by the United States.
According to the Viasna human rights centre, those found guilty on Monday include Popular Front party leader Rygor Kastushev and US lawyer Yuri Zyankovich.
Ziankovich was sentenced to 11 years in prison for "creating and leading an extremist group".
Meanwhile, Kastushev was handed a 10-year sentence for plotting "to take power by unconstitutional means".
Political scientist and literary critic Aleksandr Feduta was also jailed for 10 years while two other defendants received two-and-a-half year jail terms.
Feduta had claimed that the "coup" project was started by an officer of the Belarusian secret service (KGB) who had infiltrated the group.
The case was first reported amid widespread demonstrations in Belarus after Lukashenko's disputed re-election in August 2020.
Belarusian authorities have conducted a relentless, multi-pronged crackdown on dissent following the demonstrations.