ST PETERSBURG, RUSSIA -- APRIL 3, 2017: Police officers near Sadovaya station of the St Petersburg metro closed after a blast hit a train carriage between Sennaya Ploschad and Tekhnologichesky Institut stations at 14:40 Moscow time; according to Russian National Antiterrorism Committee several people were killed in the explosion. All St Petersburg Underground have been closed following the explosion. Alexander Demianchuk/TASS (Photo by Alexander Demianchuk\TASS via Getty Images)
