- OVD Info, which monitors detentions at opposition rallies, said police had detained more than 200 people across the country.
MOSCOW: Police on Saturday aggressively detained protesters in Moscow and other cities as thousands of supporters of jailed Kremlin critic Alexei Navalny took to the streets following his call to protest against President Vladimir Putin's rule.
In the Russian capital, which usually mobilises the largest rallies, protesters planned to meet on the central Pushkin Square at 2:00 pm (1100 GMT) and march towards the Kremlin.
But more than an hour before the planned rally police began detaining people, AFP journalists reported.
Putin's most charismatic critic put out the mass rally call after surviving a near-fatal poisoning with a Novichok nerve agent and returning to Moscow last weekend following months of treatment in Germany. He was arrested at Sheremetyevo Airport and jailed.
Protests were held early Saturday in the Far East, Siberia and the Urals including Khabarovsk, Novosibirsk and Chita where several thousand turned out, Navalny supporters said.
OVD Info, which monitors detentions at opposition rallies, said police had detained more than 200 people across the country.
Protesters told AFP they wanted to see new faces in politics and that authorities were persecuting Navalny for speaking the truth.
"The country is in a state of complete lawlessness because of Putin's rule," a young protester, Maria Kirichenko, said in the Pacific port of Vladivostok.
Saturday's rallies are expected to be a major test of the opposition's ability to mobilise despite increasing Kremlin pressure on critics and the coronavirus pandemic.
Ahead of the demonstrations, Navalny's team released a video investigation into an opulent Black Sea property allegedly owned by Putin who has been in power for 20 years. The two-hour report has been viewed more than 66 million times.
In Vladivostok, demonstrators gathered in the city centre, chanting "Putin is a thief" and "Freedom to Navalny!"
AFP footage showed riot police running after protesters and beating them with batons.
In Yakutsk south of the Arctic Circle, protesters wrapped up against the cold, rallied in temperatures of minus 50 degrees Celsius (-58 Fahrenheit).
Navalny, who is being held in Moscow's high-security Matrosskaya Tishina jail, thanked his supporters on the eve of the rallies.
"I know perfectly well that there are lots of good people outside of my prison's walls and help will come," he said Friday.
Navalny's wife Yulia said she would join the Moscow protest, "For myself, for him, for our children, for the values and the ideals that we share".
Ahead of the demonstrations several key Navalny aides including his spokeswoman Kira Yarmysh were taken into police custody for violating protest laws and handed short jail sentences.
The Investigative Committee on Friday launched a criminal probe into the calls for unauthorised protests.
A hastily organised court on Monday jailed Navalny for 30 days, and his supporters fear that authorities are preparing to sentence him to a long prison term to silence him.
The "Putin's palace" report released by Navalny alleges the Russian leader owns a 17,691 square metre mansion that sits on a property 39 times the size of Monaco.
The Kremlin has denied the property belongs to Putin.
A number of public figures -- including those who usually steer clear of politics -- have spoken out in Navalny's support.
Many took to social media -- including video sharing app TikTok popular with teens -- to urge a large turnout on Saturday.
A hashtag demanding freedom for Navalny was trending on TikTok and videos demanding Navalny's release garnered hundreds of millions of views.
Russia's media watchdog warned online platforms against encouraging minors to participate in the rallies or risk hefty fines.
The watchdog said on Friday that media platforms, including TikTok and YouTube, began removing content at its request.
Navalny, 44, rose to prominence a decade ago and has become the central figure of Russia's opposition movement, leading large-scale street protests against corruption and electoral fraud.
His arrest drew widespread Western condemnation, with the United States and the European Union calling for his release.