The Russian national flag is pictured during a march to commemorate Kremlin critic Boris Nemtsov, who was shot dead on Friday night, in central Moscow March 1, 2015. Holding placards declaring "I am not afraid", thousands of Russians marched in Moscow on Sunday in memory of Kremlin critic Boris Nemtsov, whose murder has widened a split in society that some say could threaten Russia's future. REUTERS/Maxim Zmeyev (RUSSIA - Tags: CRIME LAW POLITICS CIVIL UNREST)