Supporters of Russian opposition leader Aleksei Navalny have come out in cities across the country on October 7 for protests that could trigger harsh crackdowns by police.
Rallies and pickets have already taken place in dozens of Russian cities, including Moscow, Vladivostok, Khabarovsk, Ulan-Ude, Chita, and Stavropol.
In Putin’s hometown of St. Petersburg, authorities fenced off the square where a protest is planned for 6 p.m.
The protests were timed to take place on President Vladimir Putin's 65th birthday.
There are reports that at least seven people have been detained in the city of Samara. Detentions were also reported at a rally in Izhevsk and Yakutsk. The mayor of Yekaterinburg, Yevgeny Roizman, also appeared at the rally in his city, where 10 people were reportedly detained.
In St. Petersburg, Navalny’s campaign coordinator Mikhail Sosin and the campaign's lawyer, Denis Mikhailov, were detained. His campaign coordinators in Perm, Tver, and Stavropol were also detained, as well as numerous campaign activists across the country.
Supporters are demanding that Navalny be allowed to participate in the country’s March 2018 presidential election.
RFE/RL’s correspondent in Moscow says there are a few hundred people at central Pushkin Square. Protesters planned to march to the Kremlin but their way was blocked by police, prompting them to turn back to the square.
The protesters included several teenagers holding rubber ducks, a symbol of the protests, after reports that Russian Prime Minister Dmitry Medvedev had a special house for a duck on one of his properties.
Protesters at Pushkin Square are chanting "Putin is a thief!" "Happy Birthday!" "We are the authorities!" "Russia without Putin!" and "Free Aleksei Navalny!"
Heavy rains have hit Moscow, and many demonstrators have been drenched.
Police in Moscow have asked people over loudspeakers to disperse. There are at least 10 police vehicles in the square.
RFE/RL’s correspondent in Moscow says police in Moscow have so far been unprecedentedly restrained.
Nikita Grigoriev, 16, a Moscow schoolboy holding a rubber duck, told RFE/RL: "I'm here to demand the authorities let Aleksei Navalny campaign [for president]."
"I doubt [this protest] will make any difference, but we have to show there are many people unhappy with what's going on in the country," he added.
Lyudmila Gurova, 57, a pensioner, told RFE/RL: "We need freedom: freedom of assembly, freedom of identity, freedom to express our views about the country. This is a fascist country, I believe fascism has taken hold. For the last 26 years I have lived in social hell."
The protests come a day after a Moscow court rejected Navalny's appeal against a 20-day jail term he was handed after being found in violation of the law for publicly calling for unsanctioned rallies.
The ruling means that Navalny will remain in jail during the protests. Navalny’s election campaign chief, Leonid Volkov, was also sentenced to 20 days in jail on October 5.
The local governments of numerous cities have not granted permission for the planned demonstrations.
Another wing of the liberal opposition, the Yabloko party, criticized Navalny for organizing the unsanctioned rally and for calling on his supports to enter "deliberate confrontation with the police, under the batons of the OMON riot police."
"Such 'events' are frankly provocations aimed only at dubiously creating PR for a certain person," the party said in a statement on its website.
Ahead of the protests, Russian authorities issued warnings against holding demonstrations without official permission.
Putin's spokesman, Dmitry Peskov, told reporters on October 3 that "public calls for unsanctioned rallies and meetings are illegal...and therefore organizers of such events will be prosecuted."
Prosecutors in St. Petersburg said on October 6 that "any attempts to conduct unsanctioned [demonstrations] are a direct violation of the law."
Navalny has urged Russians to join the demonstrations, being organized in more than 70 cities nationwide, to support "political competition" in the country as he seeks to run in the upcoming presidential election.
"I understand perfectly well that that [the Kremlin] needs me to be locked up as much as possible and particularly on October 7," Navalny's spokeswoman, Kira Yarmysh, quoted him as saying in court.
Navalny's campaign team called on all "decent people" to participate in the demonstrations.
"Our demands are reasonable, simple, and lawful: political competition [and] access to presidential elections for Navalny and other candidates," it said in an October 6 statement.
It added that authorities should "leave activists, volunteers, monitors, and others alone and give them the opportunity to freely participate in election campaigns."
Navalny is a fierce critic of Putin, who has held power as prime minister or president since 1999 and is expected to seek a new six-year term in the March election. Putin is virtually assured of victory as the tightly-controlled political system leaves little room for surprises.
A 41-year-old lawyer who has produced numerous reports alleging corruption among key Putin allies, Navalny has opened more than 60 campaign offices and held rallies nationwide since announcing his bid for the Kremlin in December.
Russia's Central Election Commission, however, said in June that Navalny was ineligible to run for public office because of a financial-crimes conviction in one of two high-profile cases that he says were fabricated by authorities for political reasons.
Two previous nationwide demonstrations spearheaded by Navalny earlier this year led to mass detentions and rattled Russian officials with their substantial youth turnout.
Kremlin opponents and human rights activists say the government frequently violates the constitutional right to free assembly when it withholds permission for demonstrations or places restrictions on where and when they can be held.
The New York-based Human Rights Watch, meanwhile, said last month that Russian police are "systematically" interfering with Navalny's attempts to run for president by raiding his campaign offices, "arbitrarily" detaining campaign volunteers and carrying out "other actions that unjustifiably interfere with campaigning."
The Kremlin has dismissed Navalny, who finished second in Moscow's 2013 mayoral election with around 27 percent of the vote, as a convict and a marginal political figure.
With reporting by RFE/RL's Russian Service, RFE/RL correspondent Tom Balmforth, Current Time TV, Ekho Moskvy, Fontanka, and RIA-Novosti