More than 50,000 people poured into the streets of Moscow Saturday to protest military intervention in the Crimea in the largest opposition march Russia has seen since 2012 protests against president Vladimir Putin.

Termed the “March of Peace,” the rally comes a day before the Crimean peninsula is slated to hold a referendum on switching to Russian rule.

Many in the crowd held Ukrainian and Russian flags and chanted “The occupation of Crimea is Russia’s disgrace” and “Hands off Ukraine,” AFP reports.