The victims were identified as third-grade students from an elementary school in Henan province, according to reports.
One student was injured in the blaze at Yingcai School in Henan province’s Yanshanpu village, the Xinhua news agency reported on Saturday.
The victims were identified as third-grade elementary school students. A teacher told the state-run Hebei Daily that all of them were from the same class of nine and 10 year olds.
Firefighters managed to swiftly extinguish the blaze, which was reported at 11pm (15:00 GMT) on Friday and the head of the school was taken into custody while the authorities were investigating the cause.
The injured survivor was being treated in hospital and reported to be “in stable condition”, according to Xinhua.
China National Radio reported that some windows on the school’s dormitory building were smashed and published photos showing police cordoning off a nearby area.
Yanshanpu village lies on the outskirts of Nanyang, a city of nearly 10 million.
Little information about the boarding school is publicly available, though social media videos published earlier showed young children including kindergarteners wearing smocks with the school’s logo as well as older children learning calligraphy.
The private boarding institution with a kindergarten and an elementary school gives students a break every two weeks, but not this weekend, reported The Paper, a news outlet supported by the Shanghai government.
Many of Yingcai’s students are from rural areas, it said.
‘Too scary’
On Saturday, Chinese social media users expressed outrage about the fire and called for any safety lapses to be punished.
“It’s too scary, 13 children from 13 families, all gone in an instant … if there is no severe punishment their souls will not rest in peace,” one commenter on the Weibo social media site wrote.
China frequently experiences fires and other fatal accidents, largely attributed to lenient safety standards and inadequate enforcement.
In November, 26 people died and dozens were sent to hospital after a fire at a coal company office in northern China’s Shanxi province.
Eleven people died in July after the roof of a school gym collapsed in the country’s northeast.
In April, a hospital fire in Beijing killed 29 people and forced desperate survivors to jump out of windows to escape.
After the coal company fire in November, Chinese President Xi Jinping called for the country to “conduct in-depth investigations of hidden risks in key industries, improve emergency plans and prevention measures”.