Banmankhi Sub-Divisional Police Officer (SDPO) Kundan Kumar said that the incident occurred when an auto-rickshaw collided head on with a bus coming from opposite direction near Bhima village on NH 107 in the district.
The bus was on its way to Saharsa from Purnea while auto-rickshaw was going towards Sarsi from Banmankhi, he said.
The deceased has been identified as Shankar Sahni (35), the SDPO said.
All the four injured persons, including the one seriously injured, were admitted to Banmankhi Primary Health Centre but the doctors referred all of them to Purnea Sadar hospital for better treatment, the SDPO said.