Lawyers for leading Russian dissident Alexei Navalny say they will appeal his controversial three-and-a-half-year prison sentence for a probation violation.
A Moscow court ruled on Tuesday Navalny should serve jail time for breaking the rules of his probation when he failed to check in with authorities while recovering from a poisoning attack in Germany.
According to his lawyers, Navalny may only have to serve two years and eight months jail as a previous house arrest may be taken into account.
Navalny has been on probation since 2014 in a fraud case, which he has long condemned as political and the European Court of Human Rights said involved "arbitrary and unfair" proceedings.
Navalny argued in court there was no way he could have followed the rules, noting he was comatose at the time he was taken to Germany.
"I was being treated in Germany," Navalny told the court ahead of sentencing.
But the Russian judge insisted the terms of the probation apply whatever the circumstances.
"The court has ruled to satisfy the motion of the Federal Penitentiary Service," said judge Natalya Repnikova as she announced the decision, in comments carried by TASS.
Navalny used the proceedings to once again pin the August attack, which involved the nerve agent Novichok being applied to his underpants, on Russian President Vladimir Putin, saying the Kremlin leader will go down in history as "Vladimir, the underpants poisoner".
Navalny said the attack was orchestrated by Putin and an FSB domestic intelligence agency "hit squad" planted the Novichok in his underpants.
"We have proven that Putin committed this attempted murder," Navalny said, and now "this little thieving person in his bunker" is going crazy because he had survived.
Putin and the FSB deny involvement.
Multiple independent labs have confirmed the presence of Novichok, which was used in at least one other attempted murder linked to the Kremlin.
Navalny returned to Russia from Germany earlier this month, even though Moscow made clear he would be detained upon arrival.
Since his detention, the country has endured two weekends of mass protests and arrests.
At least 120 detentions were made on Tuesday outside the courthouse, where witnesses described apparently random arrests and violence outside building and on nearby streets.
The police presence outside the building was strong, with members of the OMON anti-terrorist units prominent. Steel barricades and other barriers were set up to keep out protesters supporting Navalny.
During a scathing courtroom attack on Putin, Navalny said the president had never engaged in politics and that "his only instrument of struggle is killing".
The dissident demanded the release of all political prisoners and called for his supporters not to be afraid.
"It's not hard to imprison me," Navalny said.
"But a whole country cannot be imprisoned."
Putin has been in power for more than two decades, alternating between the presidency and the office of prime minister.
His rule has been characterised by increasing wealth in the country but also by ever-increasing restrictions on free speech, the media and political opponents.
Prosecutors also say Navalny must pay a fine of 500,000 roubles ($A8,700). It was not clear how the court decided on this point.
During the sentencing, Navalny's wife, Julia Navalnya, broke down in tears and removed her black face mask upon hearing the news.
"See you soon. Don't be sad. Everything will be fine," he said to her in farewell.