Thousands of people gathered in downtown Moscow on Monday to protest against alleged election fraud.
Crowd numbers were estimated at “around 5,000” by a RIA Novosti correspondent at the scene. Police put the crowd at 2,000.
Opposition rallies in Moscow rarely draw more than 500 people.
There were an unconfirmed number of arrests made as the crowd gathered at downtown Moscow’s Chistye Prudy region. Influential blogger and anti-graft activist Alexei Navalny was among those detained.
“I’ve never seen anything like this. A sea of pi**ed off young Russians, revved up and loud,” Foreign Policy magazine’s Moscow correspondent Julia Ioffe wrote on her Twitter account.
Protestors called on the police to “be with the people.”
Sunday’s elections were marred by widespread allegations of poll procedure, with dozens of clips appearing to show election fraud uploaded onto the Internet.
The rally, organized by the opposition Solidarnost movement, came a day after parliamentary elections in Russia saw the ruling United Russia party suffer its worst ever result.
While the party of Prime Minster Vladimir Putin and President Dmitry Medvedev managed to hold onto a simple parliamentary majority, its share of the vote slumped from 64% to just under 50%.
The protest is continuing at Lubyanka, near the headquarters of the Federal Security Service (FSB), although crowd numbers have dropped considerably.