Wal-Mart has become the first retailer to recall eggs in China over fears of melamine contamination, AFP reported. Hong Kong authorities earlier said they had found traces of the chemical, which was responsible for the deaths of four infants and the hospitalization of thousands more after contaminating milk powder products, in eggs from the Hanwei Group. Wal-Mart has now pulled Hanwei products from its stories in the mainland, although it stressed that this was nothing more than a precautionary measure. Other supermarket chains, including French retailer Carrefour, have not issued similar recalls. The presence of melamine inside the eggs has raised concerns that the chemical, which is ordinarily used in plastics but can also boost protein levels, has been mixed into livestock feed and spread more widely through the food chain.