Police form a human chain during an anti-corruption rally in St. Petersburg on June 12, 2017. The protests were part of Navalny's long-shot drive to unseat President Vladimir Putin at the ballot box next year.
The demonstrators appeared to be predominantly younger — those who were born or grew up during Vladimir Putin's 17 years of leading Russia.
Above: Police detain a protester in Moscow.
Protesters are blocked during a demonstration in downtown Moscow.
Demonstrators in Monday's opposition protests across Russia say they are fed up with endemic corruption among officials.
A couple sits in front of riot police standing guard during an unsanctioned rally on Tverskaya Street, the capital's main street.
A young demonstrator is apprehended by riot police in downtown Moscow.
Two women react on Mars Field in central St. Petersburg. While there are no official figures on how many people have been detained, an Associated Press reporter counted about 500 people forced into police buses in St. Petersburg.
Russian police detain a protester on Tverskaya street in central Moscow.
A young woman climbs a lamp post on Tverskaya street.
Activist Yulia Galyamina and her husband Nikolai Tuzhilin lie on the ground next to riot police in central Moscow.
Police detain a young woman at Mars Field in St. Petersburg.
Russian opposition leader Alexei Navalny, right, before a court hearing in Moscow on Monday.
Riot police detain Russian opposition figure Ilya Yashin in central Moscow.
Russian police detain a protester in Moscow.
Police detain a demonstrator in central Moscow.
Police carry a detained protester in central Moscow. White House press secretary Sean Spicer told reporters on Monday that the United States "strongly condemns the detention of hundreds of peaceful protesters" which he described as an "affront to core democratic values." Spicer called on the Russian government to immediately release all peaceful protesters.
A performer dressed in a historical uniform takes part in a re-enactment festival on Tverskaya Street in central Moscow. Monday was Russia Day, a public holiday. There were men dressed in medieval armor with fur hats and swords. There were replicas of ancient wooden catapults and children were posing for pictures with the actors dressed in period costumes.