Police detained more than 4,800 people across Russia and blocked off the centre of Moscow on January 31 in a massive clampdown on protests demanding the release of jailed Kremlin critic Alexei Navalny.

Thousands of protesters defied government warnings to rally from Vladivostok to Saint Petersburg in a second weekend of mass demonstrations over the arrest of President Vladimir Putin’s most prominent opponent.

Navalny was detained at a Moscow airport in mid-January after flying back to Russia from Germany where he was recovering from an August poisoning that he blames on the Kremlin.

The 44-year-old anti-corruption campaigner is being held in a Moscow detention centre and faces years of potential jail time in several different criminal cases, despite calls from Western governments for his release.

In moves not seen for years in Moscow, authorities locked down the centre of the capital on January 31, with hundreds of police lining the streets, central Metro stations closed and restrictions on the movements of pedestrians.

Protesters who had hoped to gather outside the headquarters of the Federal Security Service (FSB) were instead scattered to various parts of the city as organisers made last-minute changes in locations.

AFP journalists saw dozens of protesters detained and taken into police vans.

Several thousand were seen marching throughout the city centre, but it was unclear amid the chaos how many people took part in the demonstration.

Independent monitor OVD-Info said at least 4,818 people had been detained across the country, after reporting more than 4,000 detentions during similar protests on January 23.

It said at least 1,365 were detained in Moscow and 962 in Saint Petersburg, as well as 82 journalists across the country.

US Secretary of State Antony Blinken on Twitter condemned “the persistent use of harsh tactics against peaceful protesters and journalists by Russian authorities for a second week straight”.

The Russian foreign ministry hit back, accusing the US of “gross interference” in its affairs and of using “online platforms controlled by Washington” to promote the protests.

EU foreign policy chief Josep Borrell also said he deplored the “widespread detentions and disproportionate use of force” against protesters and journalists.

“Russia needs to comply with its international commitments,” he added in a tweet.

Protesters chanted “Freedom!” and “Putin is a thief!” as they marched through Moscow, braving bitter cold and snow.

Several hundred protesters eventually gathered outside the Matrosskaya Tishina prison where Navalny is being held. Dozens were detained outside the complex.

“It’s almost embarrassing that the state is so afraid of us,” 31-year-old protester Elisaveta Dementieva said at the Moscow demonstration.