In Pics: St Petersburg, Russia, Subway Blast That Killed 10, Injured 50

Emergency services personnel and vehicles are seen at the entrance to Technological Institute metro station in Saint Petersburg on April 3, 2017. Around 10 people were feared dead and dozens injured Monday after an explosion rocked the metro system in Russia's second city Saint Petersburg, according to authorities, who were not ruling out a terror attack. / AFP PHOTO / Olga MALTSEVA

In this image taken from video footage filmed from a moving train on the opposite platform to where the blast occurred, people injured in blast. right, at St. Petersburg's Technological Institute metro station lay on ground, Russia, Monday, April 3, 2017. At least 10 people were killed Monday in an explosion on the subway in St. Petersburg, Russian news agencies reported. (@DARIIIIIINA via AP)