Anthony Hazzard, WHO's Western Pacific regional adviser on food safety, said the International Food Safety Authorities (Infosan) network of 167 countries is still trying to get a better picture of the flow of tainted milk from China.
Nearly 53,000 children in China have been sickened by the contaminated milk, the Chinese Health Ministry says. Four deaths have been blamed on the contaminated milk powder.
Infosan has advised countries 'to particularly focus on monitoring infant formula that may have illegally crossed borders' he told The Associated Press.
'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,' Mr Hazzard said.
China has recalled milk it exported to Bangladesh, Burundi, Gabon, Yemen and Myanmar, but it was not clear if the products sent there were contaminated or the recall was just precautionary, and if any have been sickened in those countries due to tainted milk, he added.
Melamine, used to make plastics and fertilizer, has been found in infant formula and other milk products from 22 Chinese dairy companies. Suppliers trying to cut costs are believed to have added it to watered-down milk because its high nitrogen content masks the resulting protein deficiency.
Baby formula and other milk products have been pulled from stores around China and Chinese dairy products have been recalled or banned in Japan, Singapore, Brunei, Malaysia and Hong Kong.
The Philippines has imposed a temporary ban on all milk imports from China as a precautionary move. -- AP