Around a week after the Russian parliamentary elections, which were overshadowed by allegations of manipulation, hundreds of people in Moscow protested the result.
According to a reporter from the German press agency on site, more than 1000 people gathered on the central Pushkin Square on Saturday afternoon.
The rally was called by the Communist Party, which took second place behind the Kremlin's United Russia party in the vote last weekend.
The MPs demanded, among other things, a recount of the votes cast online, which the opposition believed to have been systematically falsified.
The Russian authorities had previously warned against participating in the unauthorized protest.
The police were in large numbers around Pushkin Square.
Barriers were set up in many places.
There were many prisoner transports waiting.
In contrast to the demonstrations for the release of the imprisoned Kremlin opponent Alexei Navalny earlier this year, fewer young people responded to the call.
The police kept playing music over loudspeakers - possibly to disrupt the communists' speeches.
United Russia won the three-day vote last weekend with 49.8 percent.
The communists landed in second place with 18.9 percent.
Like all other forces represented in the Duma, they are considered to be very close to the Kremlin.
Opposition and election observers complain about massive violations of the vote count.