China is again in the spotlight as far as food safety is concerned. Ten Japanese people fell ill on Wednesday after eating frozen pork dumplings, known as gyoza, manufactured by Tian Yang Food in China's Hebei province.

The Japanese authorities announced that three people in Hyogo prefecture and seven in Chiba prefecture near Tokyo were hospitalized on Wednesday suffering from stomach aches, vomiting, and diarrhea. The Health Ministry said that among them, there is also a 5-year-old girl whose condition is critical.  

According to Xinhua, Japanese officials said that they examined the vomit of the hospitalized people and the packages they ate from. Wang Daning, head of the Bureau of Import and Export Food Safety with the AQSIQ, said on Thursday, that enough methamidophos was found to poison humans . Methamidophos is an organic phosphorus insecticide.

Wang added that Japanese authorities tested the rest of the dumplings of the same batches, over 2,000 packs, finding no traces of the insecticide. The manufacturer Tian Yang Food Plant had exported the dumplings only in Japan, and subsequent to the recent events it has recalled all exports to Japan.

China’s quality watchdog announced Thursday that samples from the frozen dumplings suspected to have sickened the Japanese people were tested and no dangerous chemicals were found.

According to AFP, Chinese foreign ministry spokesman Liu Jianchao said that before export, "the producers had tested the ginger and cabbage in the (pork) dumplings for insecticides and found the dumplings to be up to standard.”

The Japanese distributor and importer of the tainted dumplings is JT Foods, a subsidiary of Japan Tobacco Inc, who agreed to recall the dumplings from the market.

The current situation generates questioning over Chinese safety measures once more, despite the four-month quality and safety campaign initiated by China in December, after last year’s import alerts. Products such as toothpaste, toys, pet food and even seafood were reported to contain poisoning substances.

Police is investigating the situation. According to Reuters, the Japanese officials are not sure whether the contamination took place in China or in Japan. According to the same source, last year a number of Japanese manufacturers admitted to having erred in labeling production and expiry dates on cookies and rice cakes.