Updated

At least nine countries — as far away as Kenya — have banned Chinese dairy imports in response to a widening tainted milk scandal that has claimed the lives of four Chinese babies.

Several more countries, from Canada to Australia, have increased their testing of Chinese food imports amid fears that compromised ingredients may have contaminated other products, like yogurts, cookies and candies.

The scare has been most acutely felt in Asia, where worried parents on Tuesday rushed their children to hospitals for health checkups after China said that formula laced with a toxic chemical had sickened 54,000 infants.

"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."

As the reports of sick babies multiplied — with at least five reported outside the mainland in the Chinese territories of Hong Kong and Macau — even countries that don't import Chinese dairy began sounding alarms.

The European Union, for instance, urged customs authorities on Monday to step up checks on imports of "composite products," such as bread or chocolate, to ensure they contain no traces of contaminated milk.

The crisis was initially thought to have been limited 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.

Growing public fears led some schools and stores to pull more products as a 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.

Since the scandal broke earlier this month, Bangladesh, Brunei, Japan, Malaysia, Philippines, Singapore and Taiwan have placed at least partial import bans on Chinese dairy products or foods that may contain milk. Vietnam has ordered testing of all Chinese milk products and pulled several thousand gallons (liters) of milk from supermarket shelves.

Burundi and Kenya have both banned imports. Burundi's order, issued Saturday, will remain in place until 35 sacks of milk powder seized over the weekend are tested. Kenya, which does not buy Chinese milk, said it was concerned about products such as toffees and chocolates.

As import bans continued to crop up, the World Health Organization warned Tuesday that the tainted infant formula at the heart of the scandal might be smuggled across borders.

"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," said Anthony Hazzard, the Western Pacific director of the World Health Organization.

France heeded the call, saying it was checking to make sure no Chinese baby milk products have slipped into the market on a small scale. The General Directorate of Competition, Consumer Affairs and Prosecution of Fraud said Tuesday that none have been found so far.

But most consumers and regulators were focusing on legal imports.

Canada issued recalls for Mr. Brown brand instant coffee after Taiwan pulled the product off its shelves.

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

Malaysia expanded its ban on Chinese milk products on Tuesday to include candies, chocolates and any other food containing milk.

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.

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

After reports that a 16-month old in Macau developed a kidney stone after drinking Chinese-made Nestle milk powder made, the company rushed to assure consumers its products hadn't been affected.

Switzerland-based Nestle said in a statement Tuesday that its milk products sold in China and Hong Kong are "absolutely safe" and that none are made from tainted milk. No government tests have found melamine in Nestle milk products.

U.S.-based Kraft Foods Inc. issued a statement saying Oreo products with milk do not contain any dairy from China. American 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.