BEIJING (AP) -- Chinese police arrested two brothers suspected of adding a dangerous chemical to milk they sold to a company that produced infant formula that killed two babies and sickened more than 1,200 others, officials and state media reported Monday.
The two brothers, surnamed Geng, run a milk collection center in Hebei province and are accused of adding melamine, a chemical used in plastics, to the milk to make it appear higher in protein, the official Xinhua News Agency said. They sold about three tons of contaminated milk a day, the report said, citing Hebei police spokesman Shi Guizhong.
Chinese investigators say melamine may have been added to the milk to fool quality tests after water was added to fraudulently increase the milk's volume. Melamine is rich in nitrogen and standard tests for protein in food ingredients measure nitrogen levels.
China's Health Ministry on Monday said two infants have died from drinking the contaminated milk powder and 1,253 have been sickened.
Vice Health Minister Ma Xiaowei told a news conference that 913 of the infants were only slightly affected and their condition was not considered life threatening. However, 340 remained hospitalized and 53 cases were considered especially severe, he said.
No information was given about the fatalities, although authorities had earlier announced one death.
The company that produced the infant formula, Sanlu Group Co., is China's biggest producer of powdered milk and is 43 percent owned by a New Zealand dairy farmers' cooperative, Fonterra.
New Zealand Prime Minister Helen Clark said Monday she learned of the problem on Sept. 5 and convened a meeting of senior ministers three days later at which she ordered officials to directly inform senior authorities in Beijing, at a time when provincial Chinese officials appeared to be dragging their feet in ordering a recall.
"We were the whistle blowers and they leapt in and ensured there was action on the ground," Clark told reporters. "At a local level ... I think the first inclination was to try and put a towel over it and deal with it without an official recall."
Fonterra, the world's biggest milk trader, said Sunday it had urged Sanlu to recall the product as early as six weeks ago. Sanlu did not order a recall until last Thursday.
Chinese officials have defended their response to the country's latest product safety disaster but blamed Sanlu Group for delays in warning the public. Officials say they were not alerted until last Monday, even though Sanlu received complaints as early as March and company tests in August found the milk powder contained melamine, which is banned in food products.
Authorities have seized 2,176 tons of milk powder from a Sanlu warehouse and recalled 8,218 tons already sent to market, Xinhua said. It said all would be destroyed.
On Sunday, the General Administration for Quality Supervision, Inspection and Quarantine sent groups of officials to Hebei, Guangdong and Heilongjiang provinces and the Inner Mongolia region to inspect dairy companies. The teams will also work with local officials to remove all substandard milk powder from the market.
Inspectors will check the country's 175 baby milk food factories and their findings will be released within two days, said Li Changjiang, head of the safety watchdog.
The incident is an embarrassing failure for China's product safety system, which was overhauled in an attempt to restore consumer confidence after a string of recalls and warnings abroad over tainted toothpaste, faulty tires and other goods.
Associated Press writer Ray Lilley in Wellington, New Zealand, contributed to this report.