Up to 1,500 opposition activists rallied on New Pushkin Square on Saturday with City Hall's permission to call for the release of detained participants of last May's sanctioned anti-government protest on Bolotnaya Ploshchad.
Activists of non-parliamentary opposition groups including Left Front, Solidarity and RPR-Parnas protested on Saturday afternoon outside the Pushkinskaya metro station, demanding the release of 18 arrested activists, including three under house arrest, who face criminal charges of taking part in riots on Bolotnaya Ploshchad on May 6.
Protesters on Saturday also demanded the dismissal of Investigative Committee chief Alexander Bastrykin, whose agency launched the inquiry into the May 6 rally.
Left Front leader Sergei Udaltsov put the number of protesters on Saturday at about 1,500. Police said there were 500 protesters and 100 reporters. But a reporter for the state news agency Itar-Tass said there were only 200 protesters.
A similar rally in St. Petersburg on Saturday gathered 150 to 200 people.
Opposition leaders are planning a large-scale rally on Bolotnaya Ploshchad on May 6, on the anniversary of the controversial rally, which ended in violent clashes with police and more than 400 detentions. Many pundits, including members of the presidential human rights council, have accused police of provoking the violence.
A total of 26 participants are suspects in the criminal case into riots at the Bolotnaya Ploshchad rally. One suspect has been sentenced to 4 1/2 years in prison, and another is on an international wanted list.
In a separate criminal case, Udaltsov and fellow Left Front activists Leonid Razvozzhayev and Konstantin Lebedev are suspected of plotting riots at the May 6 rally with Georgian politician Givi Targamadze. Udaltsov is under house arrest, while Lebedev and Razvozzhayev stay in pretrial detention.
Lebedev pleaded guilty to the charges on Friday. Udaltsov attributed Lebedev's plea to the hope of getting a more lenient punishment. The case was sent to court by the Prosecutor General's Office that day.
The accusations against the three opposition leaders mounted after state television NTV showed men resembling Udaltsov, Lebedev and Razvozzhayev discussing the organization and financing of large-scale street protests in Russia with Targamadze.