The incident took place at Gingni in Jamjodhpur tehsil this afternoon.
Suresh Solanki, a native of Madhya Pradesh, and his wife had gone to work at a nearby farm after leaving their three children in the small hut where they lived, sub-inspector of Jamjodhpur police station L C Jesadiya said.
"Solanki and his wife work as farm labourers. The couple had two daughters -- Laxmi(4), Ghani(3) -- and 4-month-old son Shivam. The children were charred to death before anyone could rescue them," he said.