Russian police have detained more than 20 people participating in an unsanctioned antigovernment rally in the center of Moscow.
The demonstrators had gathered to protest the authorities' refusal to register certain opposition parties ahead of Russian parliamentary elections to be held on December 4.
Police moved in when the demonstrators vented their opposition to Prime Minister Vladimir Putin by chanting "Russia without Putin."
They held up a banner saying that elections without an opposition were a "crime" and distributed pamphlets.
Russian President Dmitry Medvedev is leading the ruling United Russia party into the campaign, with the aim of switching to the role of prime minister.
Putin is set to be nominated as president, an office he held for two consecutive periods from 2000 to 2008.
compiled from agency reports