Russian police detained several opposition leaders, including blogger Aleksei Navalny, Boris Nemtsov, and Sergei Udaltsov in central Moscow on December 15 at an unsanctioned protest against the government of President Vladimir Putin. There was a heavy police presence for the rally on Lubyanka Square in temperatures as cold as minus 17 degrees Celsius. Protesters began by laying flowers at a monument in honor of victims of political repressions in Soviet times. Police reported that some 700 people attended the protest. Independent sources estimated the crowd at around 2,000 people. The protesters were surrounded by vans and riot police with a helicopter circling overhead. (Reuters video)