At least 401 people have been detained in Russia since Friday while trying to pay tribute to the late opposition leader Alexei Navalny, according to data offered this Sunday by OVD-Info, an NGO that protects the rights of detainees.

The arrests have been made in 36 cities in the country, added the NGO, which has been declared a foreign agent by the Russian authorities and publishes the lists of detainees with their full names. More than half of the arrests (201) were carried out in Saint Petersburg, the hometown of Russian President Vladimir Putin.

Since Friday, law enforcement forces and plainclothes agents have been trying to remove all memorials created by Navalny’s supporters, both in monuments to the victims of political repression and in improvised places.

This happened, according to local Telegram channels, in front of the Kremlin on the bridge where the opposition leader, Boris Nemtsov, was murdered in 2015. According to the local press, numerous people pay tribute to the opposition leader by placing flowers or placing candles in designated places in their cities.

Thousands of Russians in exile have taken to the streets to protest what they consider a murder commissioned by the Kremlin. Navalny, 47, died suddenly on Friday in the Arctic prison where he had been since last December, according to the Russian penitentiary services.

His co-religionists, the opposition and the Russian independent press, and the Western foreign ministries in unison accused Putin of ordering the assassination of Navalny, the Kremlin’s number one enemy for 15 years.

Navalny, who was serving a sentence of almost 30 years in prison, was transferred to an Arctic prison in December after announcing a campaign against Putin’s re-election in the March presidential elections. Presidential spokesman Dmitri Peskov considered the accusations made by the West “unacceptable” before the results of the autopsy are known.