The students started vomiting and complained of stomach pain after consuming the meal at Boknari village under Pariya police station of the district, Paraiya Block Development Officer (BDO) Mayank Kumar Singh said.
The district administration sent ambulances to bring the ill students to Anugrah Narayan Magadh Medical College and Hospital (ANMMCH) in Gaya city.
Most of the students belong to class I and II.
Over 100 of the 260 students were rushed to hospital by worried parents but only 10 were diagnosed as ill, Singh said.
Gaya District Magistrate (DM) Sanjay Kumar Agrawal said few students fell ill, but the situation worsened due to fear and panic.
"We have sought reports from the Tekari Sub-divisional Officer (SDO) and MDM in-charge about the incident," Agrawal added.