Over 200 people have been detained in Russia as police try to stop nationwide protests in support of jailed opposition politician Alexei Navalny.
The police are also breaking up groups of his supporters gathered in the capital Moscow, ahead of a protest there.
Thousands of people have already taken part in rallies in Russia’s Far East, where there were also arrests.
Mr Navalny, President Vladimir Putin’s most high-profile critic, called for protests after his arrest last weekend.
He was detained on January 17 after he flew back to Moscow from Berlin, where he had been recovering from a near-fatal nerve agent attack in Russia last August.
On his return, he was immediately taken into custody and found guilty of violating parole conditions. He says it is a trumped-up case designed to silence him, and called on his supporters to protest.
Navalny, an ex-lawyer who has accused President Vladimir Putin of ordering his murder, could face years in jail over legal cases that he calls trumped up. President Putin has denied involvement.
Several of Mr Navalny’s close aides, including a spokeswoman, have also been detained in the run up to the demonstrations. Prominent Navalny activists are also being held in the cities of Vladivostok, Novosibirsk and Krasnodar.
Prior to the protests, Russian authorities had promised a tough crackdown, with police saying any unauthorised demonstrations and provocations will be “immediately suppressed”.
Video footage from Russia city Vladivostok showed riot police chasing a group of protesters down the street, while demonstrators in Khabarovsk, braving temperatures of about -14C (7F), chanted “Shame!” and “Bandits!”
Police in the Siberian city of Yakutsk, one of the coldest cities in the world and where the temperature was -52C, grabbed a protester by his arms and legs and dragged him into a van, video footage from the scene showed.
OVD Info, an independent NGO that monitors rallies, said that 238 people, including 56 in Novosibirsk, had been arrested so far at the rallies.
In Moscow, police put up barricades around Pushkinskaya Square as workers were engaged in re-tiling it, an apparent attempt to thwart a demonstration that was scheduled to start at 11:00 GMT. Police also arrested a few people gathered on the square before the rally.
Mr Navalny faces a years-long prison term. Authorities accuse him of violating the terms of a suspended sentence in a 2014 conviction for financial misdeeds, including when he was convalescing in Germany.
After his arrest, his team released an investigation into a lavish Black Sea resort property allegedly owned by President Putin, a claim the Kremlin denied.
The video investigation that claims the Russian President spent illicit funds amounting to £1bn ($1.37bn) on the property adding that it was paid for “with the largest bribe in history”.
The two-hour video report has been viewed more than 64 million times since its release has become the Kremlin critic’s most-watched YouTube investigation.
Mr Navalny’s arrest has drawn widespread Western condemnation, with the United States, the European Union, France and Canada all calling for his release.
