Russian riot police detained more than 500 protesters including opposition leader Alexei Navalny on Monday at rallies challenging the legitimacy of Vladimir Putin's victory in the presidential election.
Putin, who secured almost 64 percent of the votes on Sunday, portrayed his return to the presidency as a triumph over opponents who were trying to usurp power, though international monitors said the vote was clearly skewed in his favour.
But opposition leaders said they drew 20,000 people into Moscow's Pushkin Square, the scene of dissident protests during Soviet times, to call for new elections and an opening up of the political system crafted by Putin during his 12-year rule.
"They robbed us," Navalny, a 35-year-old anti-corruption blogger, told the crowd before his detention. "We are the power," he said to chants of "Russia without Putin" and "Putin is a thief."
The atmosphere at the rally was jovial at first, but became tense when riot police in helmets moved in to disperse several thousand activists who stayed on the square.
Encircling one group of protest leaders huddled in a fountain closed down for winter, black-helmeted riot police detained Navalny and others and marched them to waiting police vans.
Opposition leaders said 500-1,000 people were detained but police put the number at 250 and said 14,000 people had attended the rally.
The U.S. ambassador to Russia, Michael McFaul, said on Twitter that the arrests were troubling and that freedom of assembly and speech were universal values.
