Massive protests took place across Russia on Saturday in support of Alexei Navalny, a Russian opposition leader and vocal critic of President Vladimir Putin. Navalny was arrested last Sunday after returning to Moscow from Germany, where he was treated for a poisoning allegedly linked to the Kremlin five months earlier.

According to Reuters, about 40,000 people took part in the Moscow demonstrations, although police called that number incorrect, estimating the crowd at 4,000. Several thousands more participated in cities across the country, from Yakutsk in the northeast to St. Petersburg in the west, and about 3,000 demonstrators have been arrested in all.