The children complained of stomach ache and started vomiting after eating the snack, which was allegedly cooked a day earlier.
They were taken to a primary health centre. "The children are now out of danger," said a doctor, K.P. Naik.
Collector Ajatshatru Shrivastava told IANS on telephone: "Five children are still critical. But there condition is also improving."
School principal Deshraj Nagar has been suspended and an inquiry ordered into the incident.