The incident took place in Laugai village as lightning accompanied by heavy rains struck some people while they were on way to their home from a farmland, police said.
Two persons, identified as Rohit Kumar (12) and Ramesh Kumar (30), died on the spot, while five others sustained burn injuries, they said.
The bodies have been sent for post-mortem and the injured persons admitted to a government hospital where the attending doctors referred two critically injured persons to the Jawahar Lal Nehru Medical College at Bhagalpur, police added.