Braving bitter cold, Muscovites in favor of Russian Prime Minister Vladimir Putin and those convinced parliamentary election results were rigged took to the streets Saturday.
The dueling rallies were held about six weeks after the last major anti-government demonstrations.
Putin is seeking the presidency in the March elections and will represent his United Russia party.
The move is the latest step toward Putin's reclaiming the presidency after switching to the prime minister's office because of a law barring him from serving more than two consecutive terms as president.
Russia's third-richest man, billionaire New Jersey Nets owner Mikhail Prokhorov, is running against him.
Joining tens of thousands of marchers, Prokhorov told CNN Saturday the protesters "are my potential voters. And I will do my best to help them to live in an open, competitive Russia."FULL STORY