Customers return milk powder products at supermarket in Chengdu, in Sichuan province, 18 Sep 2008

At least 12 governments have banned Chinese dairy products or stepped up quality-testing, as China struggles to cope with its tainted-milk scandal.

Indonesia released a list Wednesday of nearly 30 Chinese-made products it says could be contaminated, including such well-known U.S.-created brands as Oreo cookies, M&M chocolates and Snickers chocolate-covered peanut bars.

New Zealand authorities say they found the chemical melamine in a Chinese-made candy known as White Rabbit, prompting the British Tesco supermarket chain to pull the candies from the shelves.

But a spokesman for the World Health Organization said on Tuesday that there have been no reports outside China and Hong Kong of infants getting sick from Chinese milk products.

China has promised to reform its quality control measures after it was revealed this month that thousands of Chinese babies were suffering kidney ailments after drinking baby formula contaminated with melamine.

The Chinese agriculture minister on Tuesday blamed so-called "milk stations," which collect milk from local farmers, for adding the substance to poor-quality milk to raise its protein content.

Chinese investigators say dairy giant Sanlu knew its products posed a health risk as long ago as December 2007, but waited until last month to report the problem.

Milk contaminated with melamine has sickened 53,000 children in China and killed four.  Nearly 13,000 children remain hospitalized, 104 of them in critical condition.