HARBIN, April 13 (Xinhua) -- More than a hundred people are still in hospital in Harbin following a mass food poisoning incident which proved fatal for a 77 year-old patient.

    The incident occurred on Monday at the Heilongjiang Provincial Hospital of Traditional Chinese Medicine in Harbin, the provincial capital.

    According to Song Chunhua, deputy chief of criminal investigation at the Harbin public security bureau, the hospital cook drew water from a boiler in the corridor of the rehabilitation center early on Monday in order to prepare a rice-based porridge.

    But the water was contaminated with fluoroacetamide, a product used to kill insects and rats.

    A total of 203 in-patients and their helpers, as well as hospital staff who ate the porridge for breakfast, fell ill. Most of them complained of nausea and diarrhea.

    Wang Enhai, deputy head of Heilongjiang Provincial Bureau of Health and chief of health emergencies in the province, said the victims were given acetamide inoculations, a specific antidote forfluoroacetamide.

    He added that eight patients out of the 203 who had fallen ill have now been discharged after undergoing a thorough and careful checkup.

    Police investigators are still trying to establish how the poison came to be in the water and in the boiler. The cook who prepared the poisonous porridge is assisting police with their investigations.