Russian opposition leader Alexei Navalny was sentenced to nine years in a maximum-security colony Tuesday, according to The Russian News Agency.
Navalny has frequently criticized the Kremlin and President Vladimir Putin, calling the latter an "obviously insane czar" for his invasion of Ukraine last month. He has also called on his country to stage daily protests against the war.
"I call on everyone to take to the streets and fight for peace," he wrote following the invasion. "Putin is not Russia. And if there is anything in Russia right now that you can be most proud of, it is those 6824 people who were detained because – without any call – they took to the streets with placards saying ‘No War’."
In 2020, Navalny was poisoned with a nerve agent and became severely ill on a flight from Siberia where he'd been campaigning against corruption and Russian leaders. He was subsequently arrested and had been serving a nearly 3-year sentence for parole violations.
Navalny reacted to Tuesday's sentencing on Twitter, quoting a line from the HBO crime drama, "The Wire."
"9 years," he wrote Tuesday. "Well, as the characters of my favorite TV series ‘The Wire’ used to say: 'You only do two days. That's the day you go in and the day you come out' I even had a T-shirt with this slogan, but the prison authorities confiscated it, considering the print extremist."
The opposition leader received support from a number of followers who heralded him a hero and derided his trial as a sham.
"#freeNavalny, [a] heroic Russian freedom fighter," Rep. Steve Cohen, D-Tenn., tweeted. "Like Zelensky he is confronted by an obdurate narcissist dictator YET they boldly speak out for justice and truth. #Navalny should be Prime Minister."
"As if I couldn't respect Navalny more, he responds to this horrific sham sentence with an Avon Barksdale quote," Liam Thorp, political editor for Liverpool Echo, said, referencing the character from "The Wire."
Others quoted another line from the HBO series to respond to Navalny's fate, "You come at the King, you best not miss."
Sen. Bernie Sanders, I-Vt., was among those demanding Navalny's immediate release.
"Why does Putin fear Alexei Navalny?" Sanders tweeted. "Because Navalny exposed Putin’s enormous corruption, and the unimaginable wealth Putin has stolen from the Russian people. That’s why Putin is trying to discredit and silence him. Release Navalny now!"
Navalny followed up his initial tweet with calls to action.
"Fighting against censorship and bringing the truth to the people of Russia has remained our priority," he wrote. "The Kremlin smashes the media, and in response we create new ones," inviting followers to subscribe to his YouTube channel, "Popular Politics."
"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," he continued, urging his supporters to not be "idle."
Russia's invasion of Ukraine began nearly a month ago. At least 925 civilians have been killed in the war up to this point, the United Nations reported.
Fox News' Peter Aitken and Amy Kellogg contributed to this report.