"The children are from class 1 to 5 and between 5-8 years of age," he said.
They suffered 30 to 90 per cent burns, Prasad, adding the condition of four is said to be critical.
Two women who tried to save the students also suffered burn injuries, Prasad said.
The students along with the women are undergoing treatment at a hospital in Varanasi.
He said soon after the incident the owner of the school locked the institute and fled.
A case has been registered and investigation is on, he said.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)