Russian police arrested hundreds of protesters who took to the streets in freezing temperatures on Saturday to demand the release of opposition leader Alexei Navalny.
The 44-year-old, who is President Vladimir Putin’s most prominent and durable foe, was arrested on January 17 when he returned to Moscow from Germany, where he had spent five months recovering from severe nerve-agent poisoning that he blames on the Kremlin.
Authorities said his stay in Germany violated the terms of a suspended sentence in a criminal conviction in a case that Mr Navalny claims was illegitimate. He is due to appear in court in early February to determine if he will serve the three-and-a-half-year sentence in prison.
More than 350 people were detained in protests in the Far East and Siberia, according to the arrests-monitoring group OVD-Info, and large demonstrations were expected in the afternoon in Moscow, St Petersburg and other cities in the European section of the country.
Several thousand people turned out for a protest in Yekaterinburg, Russia’s fourth-largest city, and demonstrations took place in the Pacific port city of Vladivostok, the island city of Yuzhno-Sakhalinsk, and the country’s third-largest city of Novosibirsk, among other locations.
Thirteen people were reported to have been arrested at the protest in Yakutsk, a city in eastern Siberia where the temperature was minus 50C (minus 58F).
In Moscow, thousands of people converged on central Pushkin Square as a police public-address system blared messages telling them not to gather closely because of Covid-19 concerns and warning that the protest is unlawful.
Helmeted riot officers sporadically grabbed participants and pushed them into police buses.
On Thursday, Moscow police arrested three top Navalny associates, two of whom were later jailed for periods of nine and 10 days.
Mr Navalny fell into a coma while on board a domestic flight from Siberia to Moscow on August 20. He had been transferred from a hospital in Siberia to one in Berlin two days later.
Laboratories in Germany, France and Sweden, and tests by the Organisation for the Prohibition of Chemical Weapons, established that he had been exposed to a Soviet-era Novichok nerve agent.
Russian authorities insisted that the doctors who treated Mr Navalny in Siberia before he was airlifted to Germany found no traces of poison and have challenged German officials to provide proof of his poisoning.
Russia refused to open a criminal inquiry, citing a lack of evidence that Mr Navalny was poisoned.
Last month, Mr Navalny released a recording of a phone call he said he made to a man he described as an alleged member of a group of officers of the Federal Security Service, or FSB, who purportedly poisoned him in August and then tried to cover it up. The FSB dismissed the recording as fake.
Mr Navalny has been a thorn in the Kremlin’s side for a decade. He has been jailed repeatedly in connection with protests and has twice been convicted of financial misdeeds in cases that he said were politically motivated.
He suffered significant eye damage when an assailant threw disinfectant into his face, and was taken from jail to hospital in 2019 with an illness that authorities said was an allergic reaction but that many suspected was poisoning.
Related: One year on, with the world in chaos, Wuhan is back to normal