The West, including U.S. President Joe Biden, blamed President Vladimir Putin for the death. Western leaders did not cite evidence.
Kremlin spokesman Dmitry Peskov said the reaction of Western leaders to the death was unacceptable and “absolutely rabid”.
Russian authorities viewed Navalny and his supporters as extremists with links to the CIA intelligence agency who are seeking to destabilise Russia. They have outlawed his movement, forcing many of his followers to flee abroad.
The death of Navalny, a former lawyer, robs the disparate Russian opposition of its most charismatic and courageous leader as Putin prepares for an election that will keep the former KGB spy in power until at least 2030.
The OVD-Info protest-monitoring group said more than 110 people had been arrested across Russia at meetings and memorials to Navalny, including 64 in Russia’s former imperial capital, St Petersburg.
Navalny rose to prominence more than a decade ago by documenting and poking fun at what he said was the vast corruption and opulence of the “crooks and thieves” running Putin’s Russia.
At the time of his death he was serving prison sentences totalling more than 30 years on a host of charges of extremism and fraud, which he denied and said were politically motivated.
His mother was travelling to the IK-3 penal colony in the Yamal-Nenets region, about 1,900 km (1,200 miles) northeast of Moscow, where he died, Russian media reported.
Navalny’s supporters – including in the West – cast him as a Russian version of South Africa’s Nelson Mandela, who would one day walk free to lead the country.
His wife, Yulia, told the Munich Security Conference that Putin bore responsibility for her husband’s death and that the world should come together to defeat the “horrific regime” in Moscow and reclaim Russia.
Some Russians, though, dismissed such a view as a classic case of wishful thinking, and pointed to an opinion poll showing that most Russians disapproved of him and that Putin was vastly more popular.
“Navalny’s death is very beneficial to Putin’s opponents,” said Sergei Markov, a former Kremlin adviser.
“They will use it to undermine the legitimacy of the presidential election in Russia, use it to not recognise Putin as the legitimate president. They are trying to present Putin not as the president of a hostile country, but as a criminal with whom no one should have to deal.”
News of Navalny’s death came just hours before Ukraine withdrew from the south of the city of Avdiivka, paving the way for Russia’s biggest advance in the country since May 2023.
At “Patriki”, or Patriarch’s Ponds, the centre of Moscow nightlife, many young Russians revelled away Friday night just hours after news of Navalny’s death. There was no sign of sadness.
“It is sad of course when anybody dies,” Olga Kazakova, a Russian, told Reuters in central Moscow on Saturday.
“But you in the West paint him as someone he was not. The West is not our friend – you are fighting against us in Ukraine.”
On the bridge beside the Kremlin where opposition leader Boris Nemtsov was shot dead on Feb. 27, 2015, flowers were also removed overnight. A makeshift vase of white and red carnations remained with a small printed piece of paper.
“Boris Nemtsov was shot in the back and murdered here,” the note said.
Policemen looked on as children made their way through the snow piled up in the shadow of Saint Basil’s Cathedral.
