The accident took place when the auto rickshaw, carrying 11 occupants to Deoghar in Jharkhand, was hit by a truck coming from the opposite direction, Katoriya police station SHO Pravesh Bharti said.
While six persons died on the spot, two persons succumbed to injuries at Katoriya Referral hospital, the SHO said.
The minor boy identified as one Santosh Yadav, who was seriously injured in the accident, has been admitted to Bhagalpur Sadar hospital, he said.
The identity of one victim could not be ascertained so far, he said.
All the occupants of three-wheeler were residents of three villages namely Kaithakura Wahdiya, Manjhibi and Phulidumar under Katoriya police station limits of the district, he said.
The bodies have been sent to Banka Sadar hospital for post-mortem, he said.