Nikita Belykh, leader of the Union of Right Forces (SPS), and human rights activist Lev Ponomaryov were among those arrested, a city official said. Mikhail Solomentsev, first deputy spokesman for the Moscow Mayor Yury Luzhkov, said police had behaved appropriately.
Solomentsev said police had thwarted attempts by members of the banned National Bolshevik Party (NBP) to initiate disorder.
Belykh told reporters that the city's refusal to allow the protest to go ahead was illegal.
Meanwhile, several hundred protestors gathered for a sanctioned march in Russia's second city, St. Petersburg, at 5:30 p.m. Moscow time [2:30 p.m. GMT]. Up to 3,000 protesters attended the march.
United Civil Front leader Garry Kasparov, an outspoken critic of President Vladimir Putin, and radical writer Eduard Limonov, NBP founder, took part in the protest.
