An opposition rally on Moscow’s Bolotnaya Square, called to mark the first anniversary of an antigovernment protest that ended in riots and hundreds of arrests, has ended peacefully. Thousands gathered on May 6 to hear leading opposition figures deliver speeches, many aimed at reminding the crowd about the fate of the more than two dozen activists who are still in detention following last year’s rally, which protested Vladimir Putin's return to the presidency. A placard on the main stage at the event read “Freedom for the Prisoners of May 6,” a phrase the crowd also chanted along with “Russia will be free” and “Putin's a thief”!

Opposition protesters listen to a speech during a major protest rally in Bolotnaya Square in Moscow, Russia, Monday May 6, 2013. Up to 20,000 Russian opposition supporters gathered for a protest on Monday, venting anger against the Kremlin and demanding the release of political prisoners. The protest came exactly one year after a demonstration a day before President Vladimir Putin's third presidential inauguration on the same square near the Kremlin ended in violent clashes between demonstrators and police. (Photo by Alexander Zemlianichenko/AP Photo)

Russian riot police secure an area outside the Kremlin during a major protest rally in Bolotnaya Square in Moscow, Russia, Monday May 6, 2013. The rally marks the one-year anniversary of a protest on the eve of Putin's inauguration that ended in clashes between police and demonstrators. (Photo by Alexander Zemlianichenko/AP Photo)

Opposition demonstrators hold posters of imprisoned protesters during a major protest rally in Bolotnaya Square in Moscow, Russia, Monday May 6, 2013. (Photo by Alexander Zemlianichenko/AP Photo)

Police trucks are parked during a major protest rally in Bolotnaya Square in Moscow, Russia, Monday May 6, 2013. (Photo by ITAR-TASS)

Russian opposition leader Alexei Navalny speaks during a major protest rally in Bolotnaya Square in Moscow, Russia, Monday, May 6, 2013. Up to 20,000 Russian opposition supporters gathered for a protest on Monday, venting anger against the Kremlin and demanding the release of political prisoners. The protest came exactly one year after a demonstration a day before President Vladimir Putin's third presidential inauguration on the same square near the Kremlin ended in violent clashes between demonstrators and police. (Photo by Mikhail Metzel/AP Photo)

A woman holds a poster reading "Putin Go Away" during a protest rally in Bolotnaya Square in Moscow, Russia, Monday, May 6, 2013. (Photo by Ivan Sekretarev/AP Photo)

Russian police officers detain an unidentified man during a protest rally in Bolotnaya Square in Moscow, Russia, Monday May 6, 2013. Up to 20,000 Russian opposition supporters gathered for a protest on Monday, venting anger against the Kremlin and demanding the release of political prisoners. (Photo by Ivan Sekretarev/AP Photo)

Russian opposition leader Alexei Navalny, right, and his wife Yulia stand during a major protest rally in Bolotnaya Square in Moscow, Russia, Monday, May 6, 2013. (Photo by Mikhail Metzel/AP Photo)

Police trucks line up on a bridge during a major protest rally in Moscow, with St. Basil Cathedral in the background, Russia, Monday, May 6, 2013. (Photo by Mikhail Metzel/AP Photo)

In this photo taken Sunday, May 6, 2012, Denis Lutskevich, left, is detained by police during an opposition rally in Bolotnaya Square in Moscow. The former naval cadet and first-year student, 21-year-old Lutskevich was attending his first protest when he was detained, and is still in prison Monday May 6, 2013, on the first year anniversary of the protest. Lutskevich is one of more than two dozen people who are still held, facing criminal charges over the involvement in the May 6, 2012 opposition protest that ended in violent clashes between demonstrators and police. (Photo by Pavel Golovkin/AP Photo)

A Russian policeman secures the area, as rescuers try to free the body of a man killed by a collapsed construction of the stage for a major protest rally in Bolotnaya Square in Moscow, Russia, Monday May 6, 2013. Moscow police say a man helping construct the stage for a major protest rally has died after a column of sound equipment collapsed. The accident at midday Monday came just a few hours before opponents of President Vladimir Putin were to gather for a demonstration. The rally marks the one-year anniversary of a protest on the eve of Putin's inauguration that ended in clashes between police and demonstrators. (Photo by Yevgeny Feldman/AP Photo)