The tablets were administered to students by doctors of nearby Syana Primary Health Centre under the UP government's Ashirwad Bal Swasthya Guarantee Yojna, Chief Medical Officer Deepak Ohri said.
He said the doctors were unware that the students were taking iron pills empty stomach.
The children suffered convulsions and nausea soon after consuming the tablets, Ohri said.
All of them were rushed to the medical centre and were discharged after first aid, he said.