HONG KONG (AP) -- Countries across Asia slapped bans on Chinese dairy products Tuesday as worried parents rushed their children to hospitals for health checkups amid a widening health scare over tainted Chinese milk.

From Japan to Thailand, reports spread of cookies, ice cream and even meat buns that might contain contaminated milk products blamed for least four infant deaths in China. At least another 53,000 others have fallen ill.

Growing public fears led some schools and stores to pull more products out of precaution. Even major international food makers such as Kraft Foods were hit by unconfirmed rumors of recalls of numerous snacks, including Oreo cookies and M&Ms.

The World Health Organization on Tuesday warned of possible smuggling of the tainted infant formula at the heart of the scandal across borders.

"I'm still worried about my child," said Mary Yu, a Hong Kong mother who took her 3-year-old son for hospital tests Tuesday, along with hundreds of other parents in the territory. "I want to have a thorough check to play it safe."

The crisis was initially thought to have been contained to Chinese milk powder laced with melamine, an industrial chemical used to make plastics and fertilizer that can cause kidney stones and lead to kidney failure.

But recent testing found melamine in samples of liquid milk taken from 22 Chinese companies -- including the country's two largest dairy producers, Mengniu Dairy Group Co. and Yili Industrial Group Co. -- and prompted nationwide recalls of milk and dairy products.

Anthony Hazzard, the Western Pacific director of the World Health Organization, said Tuesday that 82 percent of the children made sick by the formula were 2 years old or younger.

He said a network of 167 countries organized by the WHO and the Food and Agriculture Organization had been advised to focus particularly on smuggled formula. Health officials were still getting a handle on which countries may have received the contaminated products.

"I think the greatest fear is if there has been illegal movement of the heavily contaminated products rather than the legal movement of products that may have very low levels of melamine," Hazzard said.

Other countries -- including Singapore, Taiwan, Brunei, Hong Kong, Vietnam and the Philippines -- followed China's lead with their own restrictions, recalls and bans on foods that might have mainland dairy ingredients. The limits covered everything from yogurt bars to strawberry milk, biscuits and candy.

Bangladesh even ordered testing of powder milk imported from countries known for tighter government regulations such as Australia, New Zealand, Denmark.

"I'm scared after reports about the contaminated milk," said Sultana Rahman, mother of an 8-month-old baby in a Bangladesh, where the government banned three brands of Chinese baby powder milk. "I would rather breast feed my baby than giving her powder milk."

On Tuesday, Malaysia expanded its ban on Chinese milk products to include candies, chocolates and any other food containing milk. The country's Health Ministry said it was still determining how many products in Malaysia would be affected by the ban.

A major Japanese food maker, Marudai Food Co., pulled its cream buns, meat buns, and creamed corn crepes from supermarkets, but was still conducting tests to determine whether its products were contaminated.

Australian regulators said that while no milk products from China had been imported, candies and other foods would need more testing.

"We are just making sure that none of the contaminated ingredients have ended up in some of those smaller products," said Lydia Buchtmann, spokeswoman for Food Standards Australia New Zealand.

With consumer confidence shaken, international food makers said their products were safe.

Kraft Foods Inc. issued a statement saying Oreo products with milk do not contain any dairy from China. Chocolatiers Hershey and Dove offered reassurances about the safety of their products.

A spokeswoman for Mars, maker of Snickers bars, M&M candies and other sweets, did not respond to requests for comment on rumors that several Mars products might face recalls.

Contributing to this report were AP writers Dikky Sinn in Hong Kong, Farid Hossain in Dhaka, Bangladesh, Kristen Gelineau in Sydney, Teresa Cerojano in Manila, Philippines, and AP Business Writer Elaine Kurtenbach in Shanghai, China.