Hundreds of protesters angered by the impending inauguration of Vladimir Putin for a new term as president of Russian Federation demonstrated throughout the country on Saturday but were eventually arrested by the police.
In Moscow, thousands of demonstrators gathered at Pushkin Square.
Mr Navalny called for rallies in more than 90 towns and cities, including Moscow and St Petersburg.
Among the crowd on Pushkin Square were pockets of pro-Putin supporters, many of them young men. He and a group of friends were eying the riot police, trying to stay away from the clashes.
Passing on Saturday, may 5 protest action timed to the inauguration of Vladimir Putin.
Independent monitoring group OVD-Info said almost 1,600 people had been detained by police in 26 cities.
"They said that this city belongs to Putin".
"About 300 people have been detained for public order violations during an unsanctioned public event in downtown Moscow and hauled off to police precincts for questioning", the police said noting the issue of holding them accountable was under consideration.
Protesters shouted "the fourth term - in prison" and "sick of you", AFP correspondents reported. In the Urals city of Yekaterinburg, around 1,500km east of Moscow, a Reuters reporter saw more than 1,000 people protesting, some shouting "Down with the Tsar!" "Putin is not a tsar to be sitting (at the Kremlin) forever".
Protesters chanted "shame" and "Putin is a thief" while marching through the capital city, carrying placards or Russian flags.
Seventy five people were detained in the northern city of Yakutsk and more than 40 people were arrested in the southern city of Astrakhan, the monitor said.
Navalny had called for demonstrations in more than 90 towns and cities across Russian Federation against what he says is Putin's autocratic, tsar-like rule.
Videos and photos emerging from Russian Federation show what appear to be large crowds assembled for the protests. His critics have therefore dubbed Monday's inauguration- which will be held with pomp in the Kremlin's gilded halls - a coronation. Putin returned to the presidency in 2012 and was re-elected to a fourth term earlier this year. He will be in office for at least six more years, until 2024.
Putin served his first two presidential terms from 2000 to 2008. Putin was re-elected in mid-March with over 76 percent of the vote, in an election that was criticized by worldwide monitors as marked by pressure on voters and lacking real competition.