Lit candles are placed on the ground as people gather to attend a memorial service before the funeral of Russian leading opposition figure Boris Nemtsov in Moscow, March 3, 2015. Several hundred Russians, many carrying red carnations, queued on Tuesday to pay their respects to Boris Nemtsov, the Kremlin critic whose murder last week showed the hazards of speaking out against Russian President Vladimir Putin. REUTERS/Maxim Shemetov

Iraqi security forces and Shi'ite fighters reload a weapon during clashes with Islamic State militants in Salahuddin province March 2, 2015. Iraq's armed forces, backed by Shi'ite militia, attacked Islamic State strongholds north of Baghdad on Monday as they launched an offensive to retake the city of Tikrit and the surrounding Sunni Muslim province of Salahuddin. REUTERS/Thaier Al-Sudani