Moscow braced for a day of unauthorized protests on Monday after prominent opposition leader Alexei Navalny changed the location of an anti-corruption demonstration despite police warnings.
Navalny, a fierce critic of President Vladimir Putin and would-be candidate for the 2018 presidential election, released a video online late Sunday calling on his supporters to gather in central Moscow rather than the north-eastern location allocated by city officials, reports Efe news.
"We are cancelling the rally on Sakharova (street) and relocating our very peaceful event to Tverskaya (street)," Navalny said.
The move was denounced as a "provocation" by the authorities, who fear that the unsanctioned demonstrators could disrupt Russia Day celebrations due to take place around Pushkin Square and Tverskaya Street.
The annual festivities mark one of the nation's most important holidays.
Navalny said the decision to move the protest came after his organisation failed to find any companies willing to set up stages, sound systems and other crucial elements for a political rally in the area of the city allotted by officials.
Moscow's prosecutor's office said: "We are warning that any attempts to hold an unsanctioned event in Moscow will be a direct violation of the law."
It warned that authorities would take all necessary measures to prevent provocations or any action threatening public security.
In statements to a local radio station, Moscow's police chief Vladimir Chernikov warned that officers would detain anyone caught breaching peace with placards and slogans.
Smaller anti-corruption rallies were scheduled to take place in 212 cities across Russia.
Unheeding to official warnings, Navalny insisted his supporters would turn out to protest like they did on March 26, when huge unauthorized opposition rallies led to the arrest of hundreds of people including Navalny himself.
Navalny has led a grassroots campaign against perceived corruption in Putin's inner circle.
The protests in March were called to demand the resignation of Prime Minster Dmitry Medvedev.