At least eight Japanese were sickened, including a child who remains in a coma, after eating Chinese-made dumplings contaminated with an insecticide, police and health officials said Wednesday.

A family of three in western Hyogo and another family of five in Chiba, near Tokyo, suffered severe abdominal pains, vomiting and diarrhea after eating the frozen dumplings imported from China by a Japanese company, the Health Ministry said.

A 5-year-old girl in Chiba remained in a coma and her mother, two brothers and a sister were in serious condition, a Chiba police spokeswoman said on condition of anonymity in accordance with police policy.

Investigators found traces of organic phosphorus insecticide in the dumplings, their containers and the patients' vomit, the ministry said in a statement. Authorities were attempting to determine the source of the contamination, it said.

Police were investigating the case, and the ministry has ordered the dumplings' importer and distributor, JT Foods Co. Ltd. — an affiliate of Japan's largest tobacco company — to recall the product.

The dumplings were imported in November from the same Chinese manufacturer, Hebei Foodstuffs Import & Export Group Tianyang Food Processing, the ministry said.

Telephones were not answered Wednesday at the General Administration for Quality Supervision, Inspection and Quarantine, which oversees the safety of China's exports. The agency's Web site made no mention of the incident.

JT Foods distributed 13 tons of dumplings each in Chiba and Hyogo, Japan's Health Ministry said.

China's exports have come under intense scrutiny in the past year after a number of potentially deadly chemicals were found in goods including toothpaste, toys, pet food and seafood.

China's government launched a four-month campaign last August to improve the quality of Chinese products and restore international confidence in its goods. Officials termed the campaign a success.