A video uploaded on Thursday features a man, the alleged attacker, slowly walking in the supermarket and carrying a backpack, reportedly containing an improvised explosive device. A few seconds later he appears before the camera without his bag, which he, apparently, had left inside a locker, where the blast later occurred, leaving at least 13 people injured and prompting the evacuation of an estimated 50 people.
READ MORE: Blast Injures Ten in St Petersburg Shop, 50 Evacuated (PHOTO, VIDEO)
According to the Russian Investigative Committee, the device was stuffed with projectiles.