Thousands of demonstrators flooded the streets of Moscow on Tuesday to rally against Russian President Vladimir Putin.
Some of Russia's most important opposition leaders joined the protests, including leftist politician, Sergei Udaltsov, who attended the rally in spite of police orders to appear for questioning on Tuesday. Udaltsov was among a handful of opposition leaders who had been called in for interrogation.
Meet some of Russia's opposition leaders in the slideshow below.
Captions in slideshow provided by The Associated Press.