At least 100 people, including 45 children, fell ill soon after eating the food served at a wedding ceremony yesterday, they said.
They were admitted to the district hospital where condition of 35 people was said to be serious.
A doctor at the district hospital said majority of the patients have been discharged.
Similarly, 200 people fell ill after consuming contaminated food during two separate marriage ceremonies in Jarwal road area in Bahraich district last night.
Sixty people have been admitted to the hospitals.
Sub divisional magistrate J P Singh said that samples of food served in both the marriages have been taken for testing.