Thousands of protesters took to the streets across Russia Saturday in support of opposition politician Alexei Navalny, who was detained by the country's authorities on Jan. 17 at Sheremetyevo International Airport and jailed for 30 days. He had been traveling home after spending five months in Germany, where he received emergency medical treatment following his poisoning with the nerve agent Novichok.

People attend a rally in support of jailed Russian opposition leader Alexei Navalny in Moscow, Russia, Jan. 23, 2021.

The protests in scores of cities, in temperatures as low as minus 50 degrees Celsius (minus 58 degrees Fahrenheit), highlighted how Navalny has built influence far beyond the political and cultural centers of Moscow and St. Petersburg. Ignoring extreme cold and police warnings, an estimated 40,000 protesters gathered in and around Moscow's Pushkin Square, where clashes with police broke out and demonstrators were roughly dragged off by helmeted riot officers to police buses and detention trucks.

Law enforcement officers clash with participants during a rally in support of jailed Russian opposition leader Alexei Navalny in Moscow, Russia, Jan. 23, 2021.

According to The Associated Press (AP), police detained more than 3,000 people and used force to break up rallies across Russia. Navalny’s wife, Yulia Navalnaya, was among those arrested in Moscow.

A law enforcement officer detains a man during a rally in support of jailed Russian opposition leader Alexei Navalny in Moscow, Russia, Jan. 23, 2021.

Law enforcement officers stand guard during a rally in support of jailed Russian opposition leader Alexei Navalny in Saint Petersburg, Russia, Jan. 23, 2021.

Law enforcement officers stand guard during a rally in support of jailed Russian opposition leader Alexei Navalny in Moscow, Russia, Jan. 23, 2021.

An injured man looks on during a rally in support of jailed Russian opposition leader Alexei Navalny in Moscow, Russia, Jan. 23, 2021.

Law enforcement officers detain a person during a rally in support of jailed Russian opposition leader Alexei Navalny in Moscow, Russia, Jan. 23, 2021.

A woman takes part in a rally in support of jailed Russian opposition leader Alexei Navalny in Omsk, Russia, Jan. 23, 2021.

Law enforcement officers stand in front of protesters during a rally in support of jailed Russian opposition leader Alexei Navalny in Saint Petersburg, Russia, Jan. 23, 2021.

A law enforcement officer holds a baton during a rally in support of jailed Russian opposition leader Alexei Navalny in Moscow, Russia, Jan. 23, 2021.

Law enforcement officers clash with participants during a rally in support of jailed Russian opposition leader Alexei Navalny in Moscow, Russia, Jan. 23, 2021.

A man holds a placard reading "One for all, all for one" during a rally in support of jailed Russian opposition leader Alexei Navalny in Omsk, Russia, Jan. 23, 2021.

A law enforcement officer detains a woman during a rally in support of jailed Russian opposition leader Alexei Navalny in Moscow, Russia, Jan. 23, 2021.

A woman stands in front of law enforcement officers during a rally in support of jailed Russian opposition leader Alexei Navalny in Moscow, Russia, Jan. 23, 2021.

People attend a rally in support of jailed Russian opposition leader Alexei Navalny in Moscow, Russia, Jan. 23, 2021.

Law enforcement officers detain a woman during a rally in support of jailed Russian opposition leader Alexei Navalny in Moscow, Russia, Jan. 23, 2021.

A smoke bomb goes off on the street as protesters are detained during a rally in support of jailed Russian opposition leader Alexei Navalny, near Matrosskaya Tishina prison, in Moscow, Russia, Jan. 23, 2021.