The activists, some of whom waved red Communist flags, dislike the liberal and pro-business leaders at the forefront of the opposition.

Left Front leader Sergei Udaltsov told the crowd that only by staying united can they hope to pose a serious challenge to Putin.

Speakers at Monday’s rally urged activists to get factory workers to join a mass protest called for Feb. 4. Most of those who attended past protests were middle-class professionals.

The demonstrations broke out after a Dec. 4 parliamentary election in which the vote was manipulated to boost Putin’s party.