More than 1,600 people have been arrested amid mass protests across Russia over the arrest of opposition leader Alexei Navalny.

The 44-year-old, a thorn in the side of the Kremlin for years, was arrested on January 17 when he returned to Moscow from Germany, where he had spent five months recovering from a nerve-agent poisoning.

Authorities say his stay in Germany violated terms of a suspended sentence in a 2014 criminal conviction, while Navalny says the conviction was for made-up charges.

Anti-Navalny protests
Police clash with demonstrators in St Petersburg – one of dozens of cities where demonstrations are taking place (AP)
Russia Navalny Protests
Hundreds of people have been detained (AP)
A police officer under attack
A man protects a police officer as protesters attack him in the capital (AP)
Russia Navalny Protests
Riot police at a protest in Yekaterinburg (AP)
Russia Navalny Protests
A man holds a poster with a portrait Alexei Navalny with a message reading: ‘One for all and all for one’ (AP)
Police with batons
Police officers use batons during a violent encounter in the capital (AP)
Protests in Moscow
Navalny has proven to be a durable for for Vladimir Putin (AP)
A scuffle in the snow
Protests took place in freezing temperatures, sometimes as low as minus 50C (AP)
Protests in Russia
This image from St Petersburg conveys the scale of the protests (AP)
Woman in face mask
There were international demonstrations against the arrest – this woman’s face mask message translates to ‘Freedom for the Word’ as she attends a protest in front of the chancellery in Berlin, Germany (AP)