The United Nations and Western countries told Moscow before the ruling to let Navalny go and some countries have called for new sanctions after earlier penalties from the EU in response to his poisoning. Moscow told them to mind their own business.
Navalny, in a video released on Twitter after the ruling, urged Russians to take to the streets in protest.
“Don’t be afraid, take to the streets. Don’t go out for me, go out for yourself and your future,” Navalny said.
He called his treatment illegal under Russian law and lashed out at President Vladimir Putin, accusing him of throwing the criminal code out of the window in fear.
The Kremlin did not immediately respond, but has previously said that the 44-year-old politician must face justice like any other citizen if he has done anything wrong.
Around 200 hundred Navalny supporters had gathered outside the police station in temperatures of minus 18 degrees Celsius and demanded he be set free, a Reuters witness said.
Four masked police officers detained Navalny at passport control on Sunday evening, the first time he had returned home after being poisoned by what German military tests showed was a Novichok nerve agent, a version of events the Kremlin rejects.
The rouble weakened as investors weighed the risk of new sanctions against Moscow.
Lithuania, Latvia and Estonia said they wanted the European Union’s foreign ministers to discuss further sanctions against Russia on Monday for detaining Navalny, whose foundation specialises in investigations into alleged official corruption.
Some of the foundation’s targets have taken legal action and some critics have upbraided Navalny in the past for espousing overly nationalist views, something he rejects.
A possible target of any new penalties would be Nord Stream 2, a $US11.6 billion ($15 billion) project to build a natural gas pipeline from Russia to Germany. Germany has supported the project so far, arguing it is a commercial venture, and government spokesman Steffen Seibert said on Monday that had not changed.
The foreign ministers of Germany, Britain, France and Italy had earlier called for Navalny’s release and Czech Foreign Minister Tomas Petricek had said he wanted the bloc to discuss possible sanctions.
The UN human rights office called for Navalny’s immediate release and demanded due process in line with the rule of law. Both Jake Sullivan, one of US President-elect Joe Biden’s top aides, and US Secretary of State Mike Pompeo have criticised the arrest.
The Russian Foreign Ministry brushed off all the criticism.
“Respect international law, do not encroach on national legislation of sovereign states and address problems in your own country,” Russian Foreign Ministry spokeswoman Maria Zakharova wrote on Facebook.
Sergei Lavrov, Russia’s foreign minister, said Western countries’ expressions of outrage over the detention were designed to distract their citizens from domestic problems and that Moscow was unfazed by potential damage to its image.
“We should probably think about our image, but we’re not young ladies going to a ball,” Lavrov told reporters.
Moscow residents interviewed by Reuters TV were divided on Navalny’s detention, with some showing sympathy but others calling him foolish to come back.
“He probably did the right thing and acted like a real man (by returning),” said one Muscovite, Yuri Elizarov.
“But from a political viewpoint he didn’t, because nothing is probably going to change here in the coming years.”