People carry Russian national flags with attached black ribbons during a march to commemorate Kremlin critic Boris Nemtsov, who was shot dead on Friday night, near St. Basil's Cathedral in central Moscow, March 1, 2015. Holding placards declaring "I am not afraid", thousands of Russians marched in Moscow on Sunday in memory of Nemtsov, whose murder has widened a split in society that some say could threaten Russia's future. [Photo/Agencies]