According to the district authorities, the children consumed mid-day meal at the primary and junior school of Kunwarpur village in Ghatampur area yesterday.
They soon after complained of diarrhoea and vomiting and were admitted to the Community Health Centre (CHC) of Patara area.
"All the children are now out of danger. Only six of them are under observation," Dr Jai Prakash of Patara CHC said. District Magistrate Kaushal Raj Sharma said a probe has been initiated and action will be taken against the principal of the school if found guilty.