A huge crowd had gathered at an outdoor venue in the state capital Patna for the burning of effigies at dusk, part of the Dusshera festival.
Officials said the stampede happened as people were leaving at the end of the event. Television channels quoted a witness as saying there were not enough lights once the ceremony was over.
In addition to the dead, at least 15 people were taken to hospital, the police chief, P.K. Thakur said. Police are examining closed circuit television pictures to determine what had triggered the stampede.