Demonstrators demanding a rerun of Russia's recent parliamentary elections have gathered in a square in central Moscow.
About 1,000 people were reported taking part in the sanctioned protest organized by the liberal opposition Yabloko party, which failed to gain seats in the next parliament.
It comes one week after tens of thousands rallied in Moscow and other cities across the country to protest the outcome of the December 4 election in the largest protests in Russia in two decades.
The vote was won by Prime Minister Vladimir Putin's United Russia party, but the results will give the party a smaller majority in the State Duma lower house of parliament.
Meanwhile, President Dmitry Medvedev said he refuses to hear criticism from the United States about alleged fraud in the elections.
Interfax quoted him as saying "I was forced to tell [U.S.] President Barack Obama on the phone that the assessment of our elections by the U.S. is of no significance to us."
The United States has criticized the elections as unfair.
The new Duma is to have its opening session on December 21. Over 26,000 people have signed up on Facebook to attend a protest called for December 24.