The affected were admitted to two local hospitals in Xining, the capital of Qinghai Province, yesterday after they complained of nausea, diarrhoea, abdominal pain and vomiting after the banquet at a restaurant.
Eleven of them were still under medical observation and three of them were in critical condition, said Yang Zhengping, director with the intensive care unit (ICU) of Qinghai Provincial People's Hospital.
They have been given a preliminary diagnosis of suspected poisoning, according to state-run Xinhua news agency.