The raiders, groups of 50 to 60 people armed with baseball bats, check the paperwork of vendors and report any inconsistencies, RIA Novosti reported Wednesday.
Nikolai Bondarik, a co-organizer of the raids, said "there's nobody to do it but us."
A radical nationalist who is a member of the Russian opposition's Coordination Council, Bondarik said people who participate in the raids are "tired of having Dushanbe [the capital of Tajikistan] in our streets."
A local news website clams raiders have used their bats to smash fruit stands. Bondarik said the bats were for self-defense.
No violence has been reported during the so-called "Russian raids," but police said they were investigating allegations the raiders obstructed lawful street trading.
An attack last week on a Moscow policeman whose skull was smashed by a marketplace vendor triggered the raids in St. Petersburg.