The protest on July 14 was billed as a meeting between opposition leaders and their voters after signatures sponsoring several candidates were rejected by the Moscow election commission.
The Moscow mayor’s office has described the rally as “illegal” and demanded the action be postponed.
Demonstrators chanted, “We are the authority here,” “Putin is a thief,” and “Putin resign.”
Russian opposition politician and anti-corruption blogger Aleksei Navalny has not yet arrived at the rally.
Ilya Yashin, one of the candidates who saw signatures invalidated, has called on demonstrators to march with him to the mayor’s office to state their election demands.
No arrests have been reported so far.