The deceased were identified as Vinoda R, her daughter Jyothi (11) and her son Sukumar (7), Inspector J Ramesh Kumar of Gachibowli police station said.
In the wee hours of today, Vinoda poured kerosene on her children and set them on fire. She then immolated herself. They died on the spot, he said.
A suicide note purportedly written by Vinoda was found from the scene, Kumar said.
The victim wrote that she was resorting to the extreme step as her husband Narender Reddy used to harass her and was not taking care of her and their children, he said.
Her husband is absconding for the past many days, the Inspector said, adding that a case has been registered and further investigation is on.