After consuming 'prasad' in the school premises at Nuagaon around 70 people including students, parents and school staff complained of vomiting, nausea and loose motion yesterday, they said.
They were shifted to nearby hospitals at Baliapal and Basta for treatment.
Chief Medical Officer of Balasore district, Bibekananda Das said contaminated food was suspected to have caused the incident. A medical team was sent to the school and all the affected persons have recovered from illness, he said.
An inquiry has been ordered into the incident and food samples have been sent for examination, said a senior official.