Hangzhou officials have launched a recall of Ciyunxiang eggs, Xinhua, the official government news agency, reported. The eggs were produced by Green Living Beings Development Center in Changzhi, Shanxi Province.

The city's bureau of quality and technical standards tested 27 brands of eggs, finding a dangerous level of melamine only in one brand of chicken eggs. Other types of eggs, like quail, produced by the same company were also safe.

Melamine, a chemical used to harden plastics, is sometimes used to adulterate food to increase the apparent protein level. Melamine-tainted infant formula has been blamed for at least four deaths in China, and the chemical has also been found in other dairy products and led to recalls both in China and in other countries.