Kolesnikova was a key figure of the Belarusian opposition in last year's disputed presidential election.
Belarusian political activist Maria Kolesnikova has been sentenced to 11 years in jail, key figures in the country's opposition movement have said.
Kolesnikova, 39, was tried in Belarus along with her lawyer Maksim Znak who received a 10-year sentence, they added.
Belarusian opposition leader Sviatlana Tsikhanouskaya posted their sentences on social media and demanded their "immediate release".
Tsikhanouskaya's adviser, Franak Viacorka, told Euronews that the verdict was "shocking" and a "farce".
"There is no evidence of their guilt. They're absolutely innocent and they must be released," Viacorka said.
On social media, he posted a video of Kolesnikova and Znak in handcuffs and jailed in a courtroom in which Kolesnikova smiled at the cameras. Viacorka said he thought it was in part a message to continue fighting.
"When [Kolesnikova] was in the cage in the courtroom today, she wanted to send the message that she doesn't care about the sentence, she only cares about changes, and she wants all of us to continue fighting for freedom," he told Euronews.
Kolesnikova became a main figure of the opposition during last year's disputed August election which resulted in the re-election of long-time leader Alexander Lukashenko.
She previously worked with the campaign of Viktor Babariko, who was stopped from registering after being arrested on charges of bribery.
Kolesnikova faced charges of harming national security when she was detained in September 2020 after resisting authorities' attempt to force her into exile.
Kolesnikova tore up her passport at the border with Ukraine to avoid being expelled from the country.
Viacorka said that the verdict today was meant to "scare" people, not only opposition figures but also members of Lukashenko's regime. He admitted nonetheless that it was a "psychological hit" for the opposition.
**"**It's a psychological hit because Maria and Sviatlana Tsikhanouskaya and Veronika Tsepkalo became kind of symbolic leaders trio for Belarusians. And last summer, their unification sparked the protests, sparked the revolution. And right now we feel sad knowing that Maria is in jail and she can't participate," he said.
"But again, she's with us morally, psychologically. We feel her energy. I am sure we will not stop. I am sure Belarus protest will not die in vain."
The sentences have been denounced by many western countries and institutions.
The EU blasted Minsk's "blatant disregard" for human rights, adding in a statement that it also reiterated its call for the "immediate and unconditional release of all political prisoners"
The European Union estimates the number of political prisoners in this former Soviet republic to be "more than 650", according to a statement issued by the spokesman for the EU's diplomatic chief, Josep Borrell.
Faced with the repression of the Belarusian opposition, the EU adopted sanctions against the regime of Alexander Lukashenko and said in July that it was considering new measures.
Germany's government denounced the "unjustifiable conviction and the instrumentalisation of the judicial system for political persecution in Belarus", according to a spokesperson.
"We will of course continue to maintain political pressure on the regime and actively support civil society," the foreign ministry spokeswoman warned.
The UK's foreign secretary Dominic Raab said: "The conviction of Maria Kolesnikova and Maxim Znak shows that the Belarusian authorities are continuing their assault on defenders of democracy and freedom. Lukashenko's regime must end this repression and release all political detainees."