At least 15 people attending a funeral lunch for an 8-year-old girl died of food poisoning in the southern city of Hyderabad, news reports said Thursday.

Police Commissioner T.S. Rao said Wednesday's tragedy occurred when an unidentified chemical substance mistaken for salt was used to prepare the customary lunch, the Press Trust of India reported.The agency said four of the dead were children. About 20 people ate the lunch and most of them started vomiting. Two died before they could be given medical help and 13 died later at the hospital.

The remaining five were in critical condition, the news agency said.