About 800 people have fallen ill after consuming 'prasad' distributed in a religious function at Mitpukuria in North-24 parganas district, a health official said on Thursday.
The affected people include those from neigbouring villages of Kalikapur, Sardarhati and Mallikpara.
They all complained of stomach pain, loose motion and vomiting after eating 'prasad' at the ceremony on Tuesday night, the district's Chief Medical Officer (Health) Proloy Acharya said.
All 800 of them were admitted to several hospitals and Primary Health Centres on the following day, he added.
About 300 people continued to be under treatment in different health facilities including the Barasat hospital, Acharya said adding, that even on Thursday many people are coming for treatment with similar ailments.
The Health department has collected samples of the 'prasad' served on Tuesday, he said.