According to an independent protest monitoring group, police detained over 4,300 people on Sunday in Russia-wide protests against President Vladimir Putin's invasion of Ukraine.

Per the recordings released on social media by opposition activists and bloggers, tens of thousands of protestors screamed "No to war!" and "Shame on you!"

Hundreds of demonstrators were sent to jail in the Urals city of Yekaterinburg. There was a video of a demonstrator being thrashed on the ground by police in riot gear. In the city, a mural depicting Putin was defaced.

The footage and photos on social media were unable to be independently verified. Police had detained roughly 3,500 people, according to Russia's interior ministry, including 1,700 in Moscow, 750 in St Petersburg, and 1,061 in other cities.

The protests drew 5,200 individuals, per the interior ministry. At least 4,366 individuals were detained in 56 different places, according to the OVD-Info protest monitoring group.

"The screws are being tightened - technically, we are witnessing military censorship," Maria Kuznetsova, OVD-Tbilisi-based Info's spokesman, said by phone.

Authorities claim that today's protests are quite large, especially in Siberian cities where such large numbers of arrests are uncommon.

The last rallies in Russia with a similar number of arrests were in January 2021, when thousands demanded the release of opposition leader Alexei Navalny, who had been imprisoned while recovering from a nerve agent poisoning in Germany.

Short reports of Sunday's protests were carried by some Russian state-controlled media, but they did not appear prominently in news bulletins.

According to Russia's RIA news agency, police "liberated" Manezhnaya Square in Moscow, which is adjacent to the Kremlin, after arresting some participants in an unofficial protest against the military operation in Ukraine.

Putin, Russia's president since 1999, describes the invasion, which began on February 24, as a "special military operation." He claims it is intended to protect Ukraine's Russian-speaking population from persecution and to prevent the US from exploiting Ukraine as a threat to Russia.

The West has dismissed his claims as a spurious excuse for war and enacted sanctions aimed at crippling Russia's economy. Ukraine has received armaments from the United States, the United Kingdom, and a few other NATO countries.

Navalny had called for anti-invasion protests across Russia and the rest of the world on Sunday.

According to social media clips, more than 2,000 people participated in an anti-war protest in Almaty, Kazakhstan's largest city. Reuters was not able to verify the posts directly.