More than 65,000 people have shown up for a concert rally near Red Square in support of the Russian-speaking population of Crimea, a Moscow police spokesman said.
Patriotic rock musician Oleg Gazmanov is the headliner at the rally's concert, taking place on Vasilevsky slope behind St. Basil's Cathedral.
Those in attendance are waving the flags of Russia, the ruling United Russia party, and the Officers of Russia organization, Interfax reported.
People have been spotted holding signs that read "We Believe Putin," "Crimea is Russian Soil" and "We Won't Surrender What Is Ours."
Similar rallies supporting Ukraine's Russian-speaking population have also sprung up in a number of other Russian cities, including Stavropol, Novosibirsk, and Smolensk, Itar-Tass reported. However, Moscow's demonstration is by far the best attended.
Moscow police have blocked off traffic on a number of central streets, namely Moskvoretskaya Ulitsa, Ulitsa Ilinka, Ulitsa Varvarka, and the Bolshoi Mosvoretsky bridge. Additionally, access to Red Square from Otkhotny Ryad metro station has been blocked.