The incident occurred when a tempo in which the victims were travelling collided with a truck coming from opposite direction on the road under Ishipur Barahaat police station area, Deputy SP Ramanand Kumar Kaushal said.
The identity of the deceased could not be ascertained.
Two persons injured were admitted to the Pirpainty hospital, while a child was rushed to the Jawaharlal Nehru Medical College and Hospital in Bhagalpur, he said.
Of seven, only four persons have been identified as Shahnaz (40), Pairia Devi (45), her son Biro (12) and auto driver Mohammad Azad (40), Deputy SP Ramanand Kumar Kaushal said.