Russian opposition leader Alexei Navalny was on Tuesday sentenced to 30 days behind bars for organising protests ahead of President Vladimir Putin's fourth inauguration.
Judge Dmitry Gordeyev of Moscow's Tverskoi district court found Navalny guilty of arranging the "unauthorised" demonstrations.
Navalny was also found guilty of disobeying police orders in separate charges later in the day.
The court heard testimony from one of the police officers who detained Navalny who said the group of 15 police had been authorised to use physical force.
The police officer said Navalny ignored megaphone warnings that the protest was illegal.
"I consider the detention was illegal, my rights were violated," Navalny said in court, arguing he had a constitutional right to hold a protest.
Navalny's lawyer Vadim Kobzev said the trial had "clearly political motives" as Putin begins his fourth Kremlin term.
"The authorities have started forming a government and now are striving by any means to deprive Navalny of freedom, to prevent him reacting to this process."
"What happens in court really has no relation to the judgement, the judgement probably already exists... they need to observe some formal steps but it has no relation to the result," Navalny told reporters following the adjournment.
The charismatic 41-year-old politician, who was barred from challenging Putin in March's presidential election, had called on Russians to stage rallies across the country on May 5 under the slogan "Not our Tsar".
Nearly 1,600 protesters were detained in 27 cities across Russia at the anti-Putin protests called "He's not our Tsar", according to OVD-Info, an independent monitor that tracks arrests.
Around one in 10 of those arrested were minors, according to the organisation.
Navalny himself was grabbed by police and carried away by his arms and legs shortly after appearing in Moscow's packed Pushkin square.
The European Union condemned "police brutality and mass arrests" following the demonstrations, which saw officers in several cities beat protesters with truncheons and drag them along the ground.
Navalny has faced a string of charges since he became the leading opposition figure campaigning against Putin's rule at mass demonstrations in 2011 and 2012.
He was jailed three times last year for breaking rules on organising demonstrations and had to travel to Spain for surgery after one of several street attacks left him nearly blind in one eye.
Members of his team have also faced charges and young supporters have reported coming under pressure at school or university because of their involvement in his campaigns.
While in court on Tuesday, Navalny said the European Court of Human Rights had ruled in his favour after he filed a complaint over Russia's refusal to issue him with a new passport until last year, citing the fact he is serving a suspended sentence for fraud.
Russian opposition leader Alexei Navalny, who was detained during a May 5 anti-Putin rally, speaks to the media outside a court building in Moscow where he was sentenced to 30 days behind bars
Opposition supporters attended an unauthorized anti-Putin rally called by opposition leader Alexei Navalny on May 5 in Saint Petersburg, two days ahead of Vladimir Putin's inauguration for a fourth Kremlin term.