Vietnamese health authorities have found the industrial chemical melamine in powdered milk imported from Australia and three brands of cookies imported from Malaysia, raising the number of melamine-tainted products found in the country to 29, health officials said Thursday.

Nguyen Thi Khanh Tram, deputy director of Vietnam's Food Hygiene and Safety Agency, said the importers were cooperating with the agency's request to recall the milk and cookies.

The tainted Gold 1-10 milk powder was produced in Australia in May. The cookies - known as Lexus Cheese Cream, Lexus Chocolate Cream and Lexus Peanut Cream - were produced in Malaysia in May and August.

All four products were imported by companies based in Ho Chi Minh City. An unknown amount of the products was sold to consumers before the companies decided to take them for melamine testing in October.

On November 5, Vietnamese health authorities also asked market inspectors to immediately recall eight kinds of candy tainted with melamine, produced by Munchy Food Industries of Malaysia and imported by the Hoang Phuc Huy company in Ho Chi Minh City.

Some European countries permit tiny quantities of melamine in foodstuffs, but Vietnamese government rules do not, and Vietnamese authorities have made a priority in recent months of keeping melamine-tainted products off the market.

The Health Ministry has authorized 22 testing centres and dispatched 20 teams of inspectors to examine melamine content in more than 500 samples, focusing on high-risk products imported from China.

The ministry said Vietnam has not yet had any cases of children diagnosed with kidney stones caused by melamine-tainted foods. However, consumers are reluctant to buy imported milk and dairy products.

"I don't want to buy any imported milk or candy these days," said Nguyen Thuy Linh, an office secretary in Hanoi.

Melamine, an industrial chemical that causes kidney-related diseases, has been discovered in processed dairy products around the world since Chinese authorities acknowledged in September that it was widespread in milk processed by several major Chinese dairy companies. The chemical had been added by Chinese farmers to make their cows' milk appear to contain more protein.

It is used to make plastics and fertilizers.