Gunpowder source of Ukraine tram blast Gunpowder in a passenger's bag caused an explosion on a tram in Dnipropetrovsk, Ukraine, that injured eight people Monday, police said. Published: June 11, 2012 at 10:53 AM DNIPROPETROVSK, Ukraine, June 11 (UPI) -- Gunpowder in a passenger's bag caused an explosion on a tram in Dnipropetrovsk, Ukraine, that injured eight people Monday, police said. "A man, a fisherman and hunter, was carrying a bag with gunpowder, which caught fire as a result of the heat," a source told Interfax-Ukraine. All of the injured were taken to a hospital.