Riot police detain Russian opposition activists taking part in an unauthorized rally, on Triumfalnaya Square in central Moscow, late on December 6, 2011. Opposition leaders defied the Russian authorities by organizing a second mass protest in two days against Vladimir Putin's 12-year rule, despite warnings of a police crackdown and the jailing of one of the organizers.

Photos by: Ilya Varlamov; Source: LiveJournal