BEIJING (AP) -- China arrested three people Thursday for allegedly adding a toxic chemical to fresh milk to mask the fact that it was watered down and three others for selling the chemical.
The practice of adding melamine, a nitrogen-rich substance used in making plastics and fertilizers, to milk supplies is blamed for killing four babies in China and sickening tens of thousands.
The babies were sickened by powdered infant formula that authorities believe was made from tainted fresh milk. Melamine has also been found in other Chinese dairy products, including yogurt, candy and cream cookies.
More than 3,654 Chinese children remain hospitalized for kidney stones or other symptoms caused by ingesting melamine, the Health Ministry said Thursday. Three were in serious condition.
The official Xinhua News Agency said all six suspects arrested Thursday worked in Inner Mongolia, a region of sprawling grasslands that has become China's dairy heartland. Countless small dairy farms dot the grasslands, with milk collected at stations and then sold to large dairy companies.
One suspect, identified by Xinhua only by his surname Cui, ran a collection station and allegedly confessed to mixing about 25 gallons of water to 544 gallons of fresh milk. He then added 21 ounces -- about three or four cups -- of fake protein, which contained melamine, to hide the fact that it was diluted.
Xinhua said he sold the tainted batch to Mengniu Dairy Group Co. on Sept. 18 -- well after the deaths and illnesses of infants due to melamine had begun to appear in local Chinese media.
The report said police also arrested a man named Sun who ran a store in Inner Mongolia's capital of Hohhot and is accused of selling 44 pounds of the fake protein powder to Cui for $54. The powder's packaging allegedly had no description of its ingredients, date of production or name of manufacturer.
Four others were arrested on suspicion of selling melamine-tainted whey powder to milk or adding melamine products to milk.
Authorities had previously arrested 36 people in northern China's Hebei province, which is the home of Sanlu Group Co., the company at the center of the tainted milk crisis. Those arrested include Tian Wenhua, the company's chairwoman and general manager.
Melamine can cause kidney stones and lead to kidney failure in larger doses. As of Wednesday, a total of 46,717 children had been treated and discharged from hospitals, the Health Ministry said.
There have not been any more reports of deaths, the ministry said, adding that all the deaths occurred between May to August, which was before the public knew milk products were tainted.
Since authorities announced melamine was found in a host of milk products in September, the scandal has prompted a string of recalls of Chinese-made milk and products containing milk in dozens of countries.
Dairy companies say they have bought new testing labs for melamine, and are trying to consolidate farms that supply their milk in an effort to win back consumer confidence.
A United Nations report Wednesday urged the country to enact stricter laws and replace its patchwork surveillance system to help restore public trust badly shaken by a spate of food safety scandals.
Most critically, China needs a unified regulatory agency, the report said, and a place consumers can go for reliable information. The task is now split among a half-dozen government agencies, creating confusion and uneven enforcement, it said.