DNIPROPETROVSK - The explosion on a tram in Dnipropetrovsk was caused by the ignition of gunpowder in a passenger's bag, a law enforcement source told Interfax-Ukraine.
"A man, a fisherman and hunter, was carrying a bag with gunpowder, which caught fire as a result of the heat," the source said.
Another source told Interfax-Ukraine that someone "was carrying gunpowder on the tram" which caught fire for some unknown reason.