Everything you need to know about the anti-government protests in Russian Federation

The national day was picked by opposition leader Alexey Navalny for the latest round of rallies created to muster support for his bid to unseat President Vladimir Putin at next year's election.

Russian opposition leader Alexey Navalny was detained by authorities as thousands of protesters engaged in a day of nationwide anti-corruption demonstrations clashed with police on Monday.

The center of the Moscow protest is at Pushkin Square - and while NPR's Mary Louise Kelly says the crowd there is huge, she adds that it's also hard to ascertain how many people are there for Navalny's cause, and how many for the national holiday. Smaller rallies also gathered in Krasnoyarsk, Kazan, Tomsk, Vladivostok and many other cities.

The protest is the second mass action since March 26 called by Navalny, who has announced his intention to run for president next year and has drawn a new generation to the streets through a relentless online campaign.

Navalny's arrest comes during a series of arrests conducted by Russian law enforcement against the president's opponents.

Thousands of people took part in anti-corruption protests across Russian Federation on Monday in a new show of defiance by an opposition that the Kremlin had once written off as ineffectual and marginalized.

Moscow authorities had agreed to a location for a protest rally in the capital, but Navalny at the last minute called changing it to one of Moscow's main thoroughfares, citing interference in building a stage at the agreed-upon rally site.

Since rising to prominence with his fiery speeches protesting Putin's third term in power in 2012, Navalny has cemented his place as Russia's top opposition leader.

Alexei Navalny, the anti-corruption campaigner who intends to run for the presidency in March next year, has organised demonstrations against Mr Putin's rule in 145 towns and cities.

As police detained demonstrators, hundreds of others shouted slogans including "Putin is a thief" and "Shame!"

The 41-year-old activist has been an outspoken critic of what he says is a corrupt regime led by Putin and his allies - in particular Prime Minister Dmitry Medvedev - and is using allegations of government impropriety to muster support.

Hundreds of people have been detained at anti-corruption rallies in Moscow and St Petersburg. Omsk, also in Siberia, saw at least 1,500 gather on the banks of the Irtysh River, with about 2,000 attending a demonstration in Khabarovsk near the Chinese border, according to Navalny's Twitter account.

Navalny, Russia's most prominent opposition figure, has been arrested numerous times for a variety of accused crimes.

While Putin has yet to confirm his candidacy for the March 2018 polls, chief critic Navalny is already on a whistlestop tour of Russian Federation, opening campaign offices and trying to collect the 300,000 signatures needed to enter the race - despite doubts he'll be allowed to stand. In April, he suffered damage to one eye after an attacker doused his face with a green antiseptic liquid.

  • Leroy Wright