Dozens of people have been detained as police try to stop nationwide protests in Russia in support of jailed opposition politician Alexei Navalny.
Police are also breaking up groups of his supporters gathered in the capital Moscow, ahead of a large 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 last Sunday 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.
Several of Mr Navalny’s close aides, including a spokeswoman, have also been detained in the run up to Saturday’s protests.
Prior to the protests, Russian authorities had promised a tough crackdown, with police saying any unauthorised demonstrations and provocations will be “immediately suppressed”.
What’s happened so far?
Russia’s Far East saw some of the first protests on Saturday, but reports conflict over how many of Mr Navalny’s supporters turned up.
One independent news source, Sota, said at least 3,000 people had joined a demonstration in the city of Vladivostok but local authorities there put the figure at 500.
AFP footage showed riot police in Vladivostok running into a crowd, and beating some of the protesters with batons
Meanwhile protesters braved temperatures of -50C (-58F) in the Siberian city of Yakutsk.
OVD Info, an independent NGO that monitors rallies, said that more than 200 people had been detained so far in 30 cities across the country.
Unauthorised rallies are planned in more than 60 cities across the country, with one in Moscow’s central Pushkin Square due to start at 14:00 local time (11:00 GMT).
However, a number of people have already been detained at the square, where police have erected metal barriers to deter protesters. Reuters quotes a witness saying at least 100 people may have been detained there.
Meanwhile, there were reports of disruption to mobile phone and internet coverage in Russia on Saturday – though it is not known if this is related to the protests.
The social media app TikTok, which is popular among teenagers, had been flooded with videos from Russians promoting Saturday’s protests and viral messages about Mr Navalny.
Russia’s education ministry has told parents not to allow their children to attend any demonstrations.
Which aides were detained?
Several of Mr Navalny’s key aides were taken into police custody in the days leading up to Saturday’s protests, including his spokeswoman, Kira Yarmysh, and one of his lawyers, Lyubov Sobol. They face fines or short jail terms.
Ms Sobol has since been released, but Ms Yarmysh has now been jailed for nine days.
Prominent Navalny activists are also being held in the cities of Vladivostok, Novosibirsk and Krasnodar.
In a push to gain support ahead of the protests, Mr Navalny’s team released a video about a luxury Black Sea resort that they allege belongs to President Putin – an accusation denied by the Kremlin.
The video has been watched by more than 65m people.