Kremlin honour guards stand at a monument to the Governor General of Moscow between 1891 and 1905, Grand Duke Sergei Alexandrovich of Russia, during an opening ceremony in Moscow's Kremlin, Russia, Thursday, May 4, 2017. Targeted by the Social Revolutionary Combat Organization, Grand Duke Sergei Alexandrovich of Russia was assassinated by a terrorist bomb at the Kremlin. (AP Photo/Pavel Golovkin, pool), APTOPIX