Vigils and rallies were held in cities across Russia and in many world capitals to honour Russian opposition leader Alexey Navalny who died in a remote Arctic penal colony.

On Saturday, the OVD-Info protest monitoring group said more than 170 people were detained across Russia at memorials to pay their respects to and grieve for the 47-year-old politician who was a prominent opponent of President Vladimir Putin.

The federal prison service said that Navalny fell unconscious and died on Friday after a walk in the “Polar Wolf” penal colony where he was serving a 19-year sentence, prompting an outpouring of grief and shock among his supporters across the world and condemnation from world leaders.

In the capital, Moscow, hundreds of flowers and candles laid for Navalny were mostly taken away overnight in black bags. Videos and photos shared on Russian social media also showed flowers being cleared from monuments to victims of Soviet-era repression across the country.

Protests are illegal in Russia under strict anti-dissent laws, and the authorities have clamped down particularly harshly on rallies in support of Navalny.

Around the world, leaders said the Russian government was solely responsible for this death. In capitals from Tbilisi, Georgia, and Berlin, Germany, to Washington, DC, and London, vigils were held in Navalny’s memory, along with protests in front of Russian embassies.