The incident took place at about 6 AM in Chowtapalem village when Mule Saraswathi set herself and two of her kids ablaze at her residence after pouring kerosene, they said.
The trio succumbed on the spot.
Darsi Mandal Police rushed to the spot after the incident when villagers informed them following which the bodies were taken for post-mortem.
The exact reason behind the extreme step is not known but police suspect that the cause may be a family dispute, Darsi Sub-Inspector Subba Rao said.
