The victims complained of vomiting and diarrhoea after consuming food served last night at the centre and 56 of them were rushed to the Safirpur community health centre, Fatehpur Chaurasi police said.
Of the 56 taken ill, 26 persons were admitted and four in serious condition were, referred to the district hospital, doctors at the Safirpur centre said.
The remaining were discharged after medication, they said.
Meanwhile, infuriated over what they termed "stale food" at the centre, the under-training SIs lodged their protest by staging a dharna at the Hardoi-Unnao road and demanded that DG, Police Training be called immediately.
"The others who had consumed food prepared at the centre are fine," he said.
SP Neha Pandey said senior officials have been informed about the incident.