Four children died of carbon monoxide poisoning in Baogunao town of Qiaojia county, Yunnan province, on Sunday.
The local government confirmed the deaths but said the case is still under investigation.
The four children, all surnamed Chen, were reported to be from the same family. Their parents are farmers in the village and have five children.
As the temperature was low that day, the children shut the doors and windows and tried to stay warm by lighting a fire inside the house. The education bureau of Qiaojia confirmed on Thursday that the children died of carbon monoxide poisoning.
The oldest was 11 years old, while the youngest was only 4. They were found dead after their teacher noticed them absent from class on Monday.
The parents were in Kunming, Yunnan, visiting their older son when the tragedy happened.
Donations for the four victims and their family were proposed by Jiuniu Yiguanzhi School on Tuesday.
"Their deaths bring great sorrow to the parents and the whole family, we hope that every one of you can give a hand to the family to help them get through this hard time," the written proposal said.
Donations totaled 271 yuan () by Thursday. Shu Fahai, principal of Jiuniu Yiguanzhi School, said, "The donations were given to the children's parents. We also sent our condolences."
In 2012, five boys with an average age of 10 were found dead of carbon monoxide poisoning in a garbage bin in Bijie, Guizhou province.