"The three kids died in their sleep when their parents along with an infant went to a neighbour's house," Hojai Sub-Divisional Police Officer, Jyoti Ranjan Nath said.
He said the children of Sanjib Ingleng, the head of Dakkhin Kandura village and the daughter of his relative were in the thatched house when the incident took place.
The children have been identified as Somseng Ingleng (13), Dipong Ingleng (10) and Mili Rongpipi (6).
"As the village has very less population, so nobody noticed the fire or hear any cry of the children. We are not able to interrogate the parents as the mother lost consciousness due to the loss," he said.
Nath said the police are suspecting it to be a case of short circuit but the actual cause will be known after investigation.