The Russian state-owned news agency RIA reported that Navalny, who was also fined 1.2 million rubles (roughly $11,500), will appeal the guilty verdict, according to his lawyer.

Tuesday's sentence was handed down at the Pokrov penal colony by a visiting session of the Lefortovo court.

While Judge Margarita Kotova read out the accusations against him, footage showed Navalny as a gaunt figure standing beside his lawyers in a room filled with security officials. He appeared unmoved by the proceedings, looking through some court documents on a table in front of him.

After the trial, Olga Mikhailova and Vadim Kobzev, two lawyers acting for the opposition leader, were driven away in a prison van, RIA reported, before they were released a short time afterwards. According to the news agency, the lawyers were initially taken away for failing to comply with demands to unblock the road after the court session.

Navalny was first detained in February 2021 after his arrival in Moscow from Berlin, Germany, where he had spent several months recovering from poisoning with nerve agent Novichok -- an attack he blames on Russian security services and on Russian President Vladimir Putin himself.

In January, Russia added Navalny and his top aides to the "extremist and terrorist" federal registry, according to the Russian Federal Service for Financial Monitoring. His Anti-Corruption Foundation (FBK) was also banned by the Russian courts last year as an "extremist" organization.

While in prison, Navalny has denounced Russia's invasion of Ukraine via social media, advocating anti-war protests across the country as "the backbone of the movement against war and death," according to Reuters.

In another tweet on Tuesday, Navalny said: "I am very grateful to everyone for their support. And, guys, I want to say: the best support for me and other political prisoners is not sympathy and kind words, but actions. Any activity against the deceitful and thievish Putin's regime. Any opposition to these war criminals."

The latest guilty verdict handed to Navalny comes amid a growing crackdown on political dissent in Russia.

The law, according to the Committee to Protect Journalists, makes it a crime to disseminate "fake" information about the invasion of Ukraine, with a penalty of up to 15 years in prison for anyone convicted.

Days after ending his hunger strike in April, Navalny's network of regional offices for his political movement were "officially disbanded," according to his chief of staff Leonid Volkov.