Tainted milk formula in China has killed three babies and sickened 6,200 in a spreading scandal that prompted three more companies — including China's biggest dairy — to recall products, the health minister said Wednesday.

Health Minister Chen Zhu said he expects the numbers of affected babies to increase as "more and more parents take kids to the hospital."

About 20 percent of the dairy companies tested nationwide had sold products tainted with melamine, officials said. Suppliers to the companies are thought to have added the banned chemical, normally used in plastics, to watered-down milk to make it appear higher in protein.

The companies included Mengniu Dairy, China's biggest milk company, which said it was recalling its baby formula after government tests found melamine in the product.

The announcement said the recall covers three batches of formula made in January but gave no details on how much product will be affected. It did not say whether any of Mengniu's baby formula was exported.

Chen told a televised news conference that 6,244 babies had been sickened after being fed tainted milk formula, and that 158 were suffering from acute kidney failure. Chen reported the death of a third baby in eastern Zhejiang province but gave no details. The two earlier deaths had been reported in Gansu province.

So far, all the sick infants were found to have consumed milk powder produced by the company at the heart of the crisis, Sanlu Group Co., he said.

Free medical care will be provided to all affected infants and a hotline is being set up, he said. More than 1,300 infants remain hospitalized.

Sanlu's general manager Tian Wnehua was fired from her post and later detained by police, the official Xinhua news agency said. Four milk suppliers have been arrested.

Four officials from Shijiazhuang in Hebei province, where the company is based, were also fired, Xinhua said.

The head of China's quality control watchdog, Li Changjiang, said that in addition to Sanlu and Mengniu, two other companies, Guangdong-based Yashili and Qingdao-based Suncare, were recalling their products after melamine was found in their milk powder. Yashili and Suncare export their products to Bangladesh, Yemen, Gabon, Burundi and Myanmar.

The General Administration of Quality Supervision, Inspection and Quarantine had already reported that its inspectors had found melamine "in 69 batches of milk powder manufactured by 22 companies."

The nationwide inspection took test samples from 109 companies that produce baby milk powder in China. Li said another 66 companies had stopped production before the melamine problem emerged.

In Taiwan, authorities said they were banning 22 Chinese companies from exporting dairy products to the island because the companies produced tainted baby formula.

And in Denmark, Arla Foods, the Denmark-based dairy group, said that production at a joint venture in China has been suspended amid the baby formula scandal. Arla and Mengniu Dairy have a joint production plant in Inner Mongolia.

The highest concentration of melamine was found in Sanlu's milk powder, he said. Among the other companies that had melamine was Olympic sponsor Yili Industrial Co., with one batch out of 35 showing the chemical's presence, Li said.

However, Li said that safety checks of food supplies going into the Olympic Village showed no problems. Inspectors were sent to regulate suppliers two months ahead of the Olympic Games, he said.

Starting immediately, 1,400 teams with 5,000 inspectors will be stationed at all companies producing baby milk to strictly oversee the process, Li said.

Li said the government is seeking more information after Hong Kong food inspectors ordered the recall of an ice cream bar made by Shanghai Yili AB Foods because melamine was found.

Amounts of the chemical found "would not pose major health effects from normal consumption of the bar, however, small children should not eat it," Hong Kong's Center for Food Safety said in a notice posted on its Web site.

It is the second crisis to raise questions about government accountability in China since the image-boosting Olympics ended Aug. 24. At least 258 people died last week when a retaining wall of a waste dump at an illegal mine in northern China collapsed.

The widening scandal is an embarrassing failure for China's product safety system, which was overhauled to restore consumer confidence and preserve export markets after a string of recalls and warnings abroad last year over tainted toothpaste, faulty tires and other goods.

It is the second major case in recent years involving baby formula. In 2004, more than 200 Chinese infants suffered malnutrition and at least 12 died after being fed phony formula that contained no nutrients.

Sanlu company officials as well as government officials share the blame for delays in reporting the contamination, said Hebei deputy governor Yang Chongyong, who spoke on the sidelines of the press conference.

Sanlu did not inform the Shijiazhuang municipal government until Aug. 2, after delaying for five months, Yang said. Then city officials waited until Sept. 9 to inform provincial officials, who then took a full day before contacting the central government, he said.