The incident took place in Panchmala locality of Jehanabad town late last night as some unidentified persons threw acid on the woman, a widow and her two children, through the window of their ground floor room while they were fast asleep, Town police station in-charge S K Shahi said.
While the woman suffered severe burn injuries and was rushed to Patna Medical Medical College and Hospital (PMCH) at the state capital, her two children were undergoing treatment at Sadar hospital in Jehanabad, he said.
A probe was on in the matter, the police officer added.