Thousands rally in Russia, challenge Kremlin

More than 120 were detained, according to Open Russia, an opposition group that provides legal aid.

Navalny was arrested, along with hundreds of others, and was jailed for 15 days after being convicted of disobeying a police officer.

White House spokesman Sean Spicer speaks during the briefing at the White House in Washington, DC, on June 12, 2017.

Other images from the day show thousands of demonstrators in St. Petersburg chanting slogans against Putin - and black-clad police marching through the crowd, making arrests and pulling people off of monuments. It adds that the opposition leader ran into problems setting up a planned demonstration on Sakharov Avenue, and instead told his allies on Sunday to gather on Tverskaya Street.

Police detain a protester during a demonstration in downtown Moscow Monday.

Regardless of his arrest, anti-corruption rallies have taken place all over Russian Federation, ending up with hundreds, possibly even thousands of arrests of demonstrators. Similar crowds turned out in March, rattling officials who had perceived the younger generation as largely apolitical.

Why was Alexey Navalny arrested?

He was detained at his home in Moscow earlier on Monday, ahead of anti-corruption demonstrations in Russian Federation.

Navalny himself was arrested Monday afternoon outside his home in Moscow as he headed for an unsanctioned protest rally.

Earlier in April, Navalny was released from custody after serving a 15-day sentence for "disobeying the police during an unauthorized rally" which he received after the March 26 anti-corruption protests in Russian Federation.

An Associated Press reporter has counted more than 200 people arrested by police at an unsanctioned opposition rally in St. Petersburg.

In Moscow, the detentions began even as demonstrators exited the metro station at Pushkin Square, a central square in the capital, and made their way toward Tverskaya. Police confirmed 650 detentions in the two cities.

Tverskaya Street, known in Soviet times as Gorky Street, is one of Moscow's main thoroughfares.

Authorities in Moscow had authorized a venue for the protest away from the city center.

Police in Moscow also warned that they would be tough on any act of provocation during the Russia Day commemorations, saying any such act would be "a threat to public order and will be immediately suppressed".

A wave of antigovernment demonstrations rolled across Russian Federation on Monday as thousands of people gathered in scores of cities to protest corruption and political stagnation despite vigorous attempts by authorities to thwart the rallies.

The re-enactors watched the rally before riot police broke up the crowd and randomly seized the protesters.

Thousands of Russians are expected to protest against corruption on Monday, part of opposition leader Alexei Navalny's long-shot drive to unseat President Vladimir Putin next year by tapping voter anger over what Navalny says is runaway official graft.

Navalny's Fund for Fighting Corruption had been providing updates on protests throughout the country Monday.

Electricity in his office was cut at around the same time as he was detained, briefly bringing down a live feed of the protests, Navalny's spokeswoman said. Police vans and buses waited on the sidelines to haul off those detained.

Teenager Anna Meigan said she was detained as she protested in Moscow.

Mr. Navalny's team have been broadcasting about the various actions from a studio set up in Moscow, but it went off air just as Mr. Navalny was being picked up by police.