As soon as the children consumed the meal at Juggaur primary school in Chinhat block around noon, they began vomiting and complained of loose motions.
Locals and parents rushed the children to the nearby Lohia hospital in Gomtinagar where the condition of a few was said to be serious.
Senior district and education department officials rushed to the hospital to oversee the treatment.
Angry parents created a ruckus at the school and allowed the staff to leave only after the intervention of some elders.
In the past too, many cases in which stale and poor quality food was served to children have come to light.