Rights group OVD-Info on Saturday claimed more than 400 people were detained by Russian authorities for paying tributes to President Vladimir Putin's key opponent Alexei Navalny across various cities in the country.

"401 DETAINED," the group said on its website.

It said people were detained across 36 cities in Russia.

On Saturday, police in Moscow detained about 15 people who had laid flowers and lit candles at the foot of the "Wall of Grief" monument to the victims of repression during the Soviet-era, reported BBC.

Reacting to the Russian politician's death, the group earlier said in a statement: "Navalny’s death was a murder — a planned murder, a murder methodically carried out, a murder of which the Russian state is guilty. Including those very agencies that are now talking about investigations."

Navalny’s spokesperson, Kira Yarmysh, said authorities have denied giving the body of the politician to his family until the investigation into his death is completed.

"Now the Investigation Committee says directly that Alexey's body will not be handed over to his relatives until the investigation is complete," she posted on X.

What happened to Navalny?

47-year-old Alexey Navalny died in an Arctic prison on Friday (February 16, 2024).

He was serving a 19-year term.

Alexey Navalny felt unwell in prison after a walk and lost consciousness. He received all necessary resuscitation measures, but they did not yield positive results, the Federal Ptnitentiary Service stated as quoted by Russia's Sputnik news agency.

President Vladimir Putin did not comment on the issue since his death was announced.

Several world leaders, including Canadian PM Justin Trudeau and US President Joe Biden, have slammed Putin over the politician's death.