The incident happened during an altercation between some villagers in Machaha village under Triveniganj police station.
Sunil Kumar, investigating officer of Triveniganj, said: "A puja was organised in the house of one Rupesh Shah. As per the ritual, the family members of Shah spread pop corn in the adjoining areas including in front of the house of one Anmol Yadav."
Yadav objected to the spreading of corn and asked them to do that away from his house, leading to a verbal duel between them. It turned ugly when both sides attacked each other using batons and iron rods.
During the altercation, one of the family members allegedly threw an acid bottle on the group of persons led by Anmol Yadav.
Five persons -- Chandrashekhar Singh, Bablu Kumar, Om Prakash Kumar, Tarun Kumar and Amit Kumar sustained severe burn injuries after they came under the impact of acid, Kumar said on Tuesday.
"They were initially admitted to a sub-divisional hospital in Triveniganj where doctors referred them to Sadar hospital after their condition became critical," he said.
An FIR has been registered against Shah and other accused and an investigation is on, the police officer said.