May 4 (UPI) -- Russian police arrested supporters of opposition leader Alexei Navalny ahead of protests against President Vladimir Putin's inauguration.
Navalny, a staunch opponent of Putin -- who is scheduled to assume his fourth presidential term Monday -- called on supporters to gather in at least 90 cities for "He's Not Our Tsar" protests on Saturday.
Moscow's City Hall granted permission for opposition representative to hold a rally on Saturday in downtown Moscow.
However, supporters of Navalny were detained in six Russian cities leading up to the protests -- including in St. Petersburg, Krasnoyarsk, Tambov, Krasnodar and Cheboksary.
Some of the opposition supporters were being held on charges of violating public assembly laws and resisting arrest.
Other volunteers were apprehended and eventually released in Kemerovo and Ryazan.
Navalny was barred from running in Russia's March presidential election due to a criminal conviction and was detained in January during a rally to support a boycott of the elections.