Russia's top opposition leader Alexei Navalny on Tuesday called for mass protests to "destroy" President Vladimir Putin's regime after a court jailed his brother in a controversial fraud case.
In a lightning hearing that was abruptly brought forward two weeks, a judge found both Navalny and his brother Oleg guilty of embezzlement and sentenced the siblings to three and a half years.
But while Navalny's sentence was suspended, his younger brother was ordered to serve the time behind bars in what observers saw as an attempt to muzzle the Kremlin's top critic by taking his brother hostage.
"This regime does not just destroy its political opponents, that is what we are used to... now they target, torture and torment the relatives of its political opponents," the charismatic Navalny said outside the Moscow courtroom after his handcuffed brother was led away.
"This regime has no right to exist, it must be destroyed," said the man who emerged as a key figure in the mass opposition protests that rocked Russia in the winter of 2011-12. "I call on everyone to take to the streets today."
Navalny supporters had already been planning to gather later on Tuesday near the Kremlin after the reading of the verdict and police have already barricaded the central Manezhnaya square in a move to preempt the demonstration.
Tuesday's hearing was a rushed affair -- first the court abruptly moved it forward two weeks to just before the New Year -- Russia's biggest holiday -- in a move seen as a tactic to avoid massive protests.
And the reading itself took only about 15 minutes -- unusually for Russia where judges usually read sentences for hours, outlining the prosecution's proof and witness testimonies.
The Navalny brothers were accused of defrauding French cosmetics company Yves Rocher of nearly 27 million rubles (more than half a million dollars at the exchange rate at the time), although the firm has said that it suffered no damages.
Prosecutors had asked the court to jail Alexei for 10 years and Oleg for eight.
"What are you jailing him for, what sort of disgrace is this?" an angry Navalny yelled, slamming his fists on the table, as Judge Yelena Korobchenko read his brother's verdict. "This is to punish me even more?"
"Of all types of verdicts this is the most mean, the most disgusting type," the 38-year-old said after bidding his handcuffed brother goodbye.
Observers saw the sentence as an attempt to control Navalny, a charismatic protest leader who galvanised the opposition with attacks on Putin and the ruling regime, exposed the exorbitant wealth of the country's elite.
The maverick politician has seen a half a dozen criminal cases lodged against him and his allies, which he says are politically motivated, and has been under house arrest for months.
"In essence, Oleg has been taken hostage, and Navalny will get discredited due to innocent people sent to jail because of him," opposition politician Boris Nemtsov wrote on Facebook.
"This is the worst moral torment they could have administered to Alexei Navalny," defence lawyer Olga Mikhailova said.
As the verdict hearing got under way, dozens of protesters crowded outside the Zamoskvoretsky courtroom in central Moscow and were pushed away from the building by police, with at least one person detained.
Moscow police warned that any "public disorder" will be followed with punishment.
Navalny's sentencing hearing was originally due to take place on January 15 and was abruptly moved forward on Monday after some 15,000 people pledged to attend a rally on that day.