Separately, the Health Ministry reported 3,503 cases of food poisoning nationwide in the second quarter of this year, including 70 deaths. Most fatalities occurred in private homes, with poisonous plants and animals blamed in 37 percent of cases and chemical contaminants in 27.8 percent, the ministry said.

Wholesale pork prices were nearly 75 percent higher in July than a year earlier, prompting widespread reports of butchers selling meat from diseased pigs or injecting water into their product to increase its sale weight. The higher prices are blamed on a shortage of the meat, partly because of an outbreak of blue ear disease, which has killed tens of thousands of pigs in recent months.

"Industrial and commerce departments at all levels should strike hard and strictly fight against the practice," said a notice posted on the government's Web site issued by six ministries, including health, agriculture and public security.