Sulekha Devi of Bhatgawan village set her two children, Kajal Kumari (4) and Krishna Kumar (2), on fire after pouring kerosene oil on them while they were asleep in a room, Babubarhi police station in-charge B K Singh said.
Both children died on the spot, he said, adding the bodies have been sent for post-mortem to a government hospital.
The woman took the extreme step in a fit of rage following a bitter quarrel with her husband Ayodhya Singh over a family-related matter, Singh said.