The tragedy occurred in Venkatapur village of Mandamarri mandal past midnight.
The fire broke out in the house of Shivaiah when all the victims were asleep, the police said.
Shivaiah (50), his wife Padma (45), Padma's nephew Mounika (23), her two daughters and another relative Shantaiah (52), an employee of Singareni Collieries, were burnt alive.
On receiving of the information, fire fighting personnel rushed to the scene and doused the fire.
The house was completely gutted.
Deputy Commissioner of Police Akhil Mahajan said that a short circuit is suspected to have resulted in the fire.
He said the exact cause will be known after a thorough investigation.
Police registered a case and shifted the bodies to Mancherial for autopsy.
(WIth inputs from IANS)
