Flowers are laid at the "Leningrad" stela to mourn the victims of an explosion in St. Petersburg, in Moscow, Russia, on April 3, 2017. Russian Health Minister Veronika Skvortsova said at least 10 people had been killed and 37 others were injured in an explosion of an unknown explosive device with destructive elements in St. Petersburg. (Xinhua/Oleg Brusnikin)
