In Nan province, the villagers ate soup containing the fish balls at a funeral. After the funeral, guests started vomiting, complaining of numbness in the tongue and shortness of breath.
They were taken to Ban Luang district hospital which later referred some of the more seriously-ill patients to Nan provincial hospital, the Bangkok Post, a local newspaper, reported on Sunday.
The fish balls were bought at a local market and the meat from the toxic fish is sometimes used illegally because it is cheap in Thailand.
Pisit Sriprasert, of the Nan provincial health office, told the newspaper all the patients admitted to local hospitals were guests at the funeral.
The patients' symptoms suggested they had consumed puffer fish meat, which contains the potentially deadly poison tetrodotoxin, which attacks nerve cells, according to Dr. Pisit.
