At least seven persons were killed and eight others injured when explosives, to be used for mining, went off inside a room in Obra town in Sonbhadra on Thursday. The incident took place in Rasprehari mining area of Sonbhadra district. The injured were rushed to a hospital. Their condition was stated to be serious, police said. The identity of the deceased persons could not be ascertained till late evening, police said, adding that the debris was being removed as it was suspected that more people might be trapped inside it. The incident comes close on the heels of a similar explosion in Madhya Pradesh’s Jhabua district in which 88 people were killed.