Vice Minister of Health Ma Xiaowei said special hospitals had been appointed nationwide to launch treatment for all the infants with the stones.

"With scientific, timely and effective treatment, we will try our best to avoid further deaths." he said.

Sanlu Group began to get complaints about its baby formula milkpowder in March and then confirmed the problems through its own investigation. It also took actions to recall some of these products. However, for a long time after that the group didn't report it to the government, neither did it reveal the information to the public, according to authorities.

Melamine is used in plastics and other industries and is strictly forbidden in food processing. Experts say it is added into raw milk so that the protein content of the milk appears higher than it is actually.

Police in Hebei have detained 19 people in connection with the scandal.

Two brothers surnamed Geng in Zhengding County, Hebei, told police that they had been selling three tons of contaminated milk per day since the end of last year.

The elder Geng said they added the chemical into the milk to make it appear to contain more protein as they had suffered losses after their milk had been rejected several times by Sanlu Group for failing to meet quality standards.

Geng confessed to police that his family never drank the contaminated milk and he was aware that he was deceiving the Sanlu Group by adding the chemical into milk.

Authorities have so far seized 2,176 tons of milk powder in the warehouse of Sanlu Group. Some 8,218 tons on the market had been recalled, said Shijiazhuang Vice Mayor Li Jinlu on Monday.

Another 700 tons of the milk powder was on their way back to Shijiazhuang, Li added. All the tainted milk powder will be destroyed.

Sanlu, which is 43 percent owned by New Zealand dairy company Fonterra, has been ordered to halt production.

(Xinhua News Agency September 16, 2008)