Interior Ministry officers stand guard during a sanctioned rally in Bolotnaya square to protest against violations at the parliamentary elections near the Cathedral of Christ the Saviour in Moscow December 10, 2011. Tens of thousands of protesters took to the streets of cities across Russia on Saturday to demand an end to Vladimir Putin's rule and complain about alleged election fraud in the biggest show of defiance since he took power more than a decade ago. REUTERS/Anton Golubev (RUSSIA - Tags: POLITICS ELECTIONS CIVIL UNREST)