January 24, 2021: Police clashed violently with protesters in Moscow and arrested more than 2,500 demonstrators in cities across the country on Saturday as Russians took to the streets to denounce Kremlin rule and demand the release of opposition leader Alexei Navalny.

Tens of thousands nationwide answered Navalny's call to rally, issued after he was detained at a Moscow airport on arrival from Germany, where he had been recovering from a near-fatal poisoning with a nerve agent.

Washington and Brussels condemned the arrests and other tactics used against demonstrators, with EU foreign policy chief Josep Borrell saying the bloc would discuss "next steps" on Monday.

Saturday's protests took on an unprecedented geographic scale, spanning more than 100 cities across the country. Previous large-scale opposition demonstrations in 2012 and 2019 were largely centralised in Moscow.

They were also being seen as a test of the opposition's ability to mobilise ahead of parliamentary elections later this year, despite increasing Kremlin pressure on critics.

In Moscow, protesters spilled out over Pushkin Square and pelted heavily armed riot police with snowballs. They were beaten back by law enforcement wielding batons and detained in large numbers.

The demonstrators marched towards the Kremlin before dispersing, and at one point massed on the steps of Moscow's circus, illuminating the crowds with hundreds of cell phone lights and pummelling a police van with snowballs.

"Criminals dressed in uniforms are protecting criminals at the helm," Vera Spivakova, a 71-year-old pensioner said in Moscow.

"Putin and the oligarchs are afraid of losing their trough," she said.