"Five young people were detained during the rally," he said, adding that they all belonged to the Rossiya Molodaya (Young Russia) movement.
More than 200 people attended the rally in the centre of the Russian capital to demonstrate against the social policies of the Moscow city government. Authorities had given the organizers permission for 500 participants.
The protesters' main grievances were the administration's "irresponsible" construction policies and "illegal evictions."
A leader of one of the opposition groups that took part, the Avangard Krasnoi Molodyezhi movement (Advance Guard of the Red Youth), earlier said that the opposition would demand the dismissal of the Moscow administration.
"The policies being carried out by the administration [of Moscow] are making the city almost unfit to live in," Sergei Udaltsov said.