BEIJING - CHINA vowed to choke off toxic milk from reaching processors and export markets after an infant powder scandal that has made more than 50,000 children sick and mired the country's trade reputation in fresh crisis.

Milk powder adulterated with the industrial chemical melamine has led to nearly 13,000 Chinese infants being admitted to hospital, 104 of them in a serious condition with kidney stones and agonising complications.

So far outside the mainland, a three-year-old girl in Hong Kong has been stricken by illness blamed on the toxic Chinese milk.

A second victim, a four-year-old boy, has been reported to be ill with a kidney stone. According to a statement by the Hong Kong Centre for Health Protection, he is in a stable condition.

With the scenes of sick infants and frantic parents alarming Chinese citizens and foreign companies and consumers, the Commerce Ministry and Agriculture Ministry late on Monday vowed a fresh shake-up of dairy and other products.

Agriculture Minister Sun Zhengcai said he would wage a 'battle' to clean up the merchants blamed for selling adulterated milk on to dairy companies.

'There can be no compromise in fulfilling every task of the clean-up,' Mr Sun said, according to a report on the ministry website.

He singled out the 'milk stations", which collect fresh supplies from often scattered farms. They have been blamed for watering down milk and adding nitrogen-rich melamine, fooling quality checks measuring protein, which is also rich in nitrogen.

Many of these stations were unregistered and unregulated, Sun said. 'The intermediate link in purchasing raw milk is basically out of control,' he said. 'These grave problems and this state of disorder have reached the stage where a clean-up is unavoidable.'

'Strict Inspections'

The milk scare had had an 'adverse effect on the reputation of our products", the Commerce Ministry said in a directive.

'There will be strict inspections of businesses producing and exporting dairy products, food, pharmaceuticals, toys, furniture and other things concerning physical safety.'

The Philippines became the latest country to order an immediate ban on the import and sale of Chinese diary products. Markets that have banned or recalled Chinese milk products include Bangladesh, Brunei, Burundi, Gabon, Hong Kong, Japan, Malaysia, Myanmar, Singapore,Tanzania, Vietnam and Taiwan. Taiwan banned all mainland dairy products from Sunday.

Canada has expanded checks for possibly tainted Chinese dairy products and the European Union will this week issue an expert opinion on whether processed goods with Chinese milk ingredients pose a health threat.

The scandal claimed its biggest political scalp so far on Monday with the resignation of China's product-safety watchdog chief Li Changjiang.

Mr Li had overseen the ministry-level agency in charge of product quality amid a wave of scandals that have tarnished China's manufacturing reputation.

Also sacked was Mr Wu Xianguo, the top Communist official of Shijiazhuang. The city's mayor and several other government officials had been fired earlier.

Eighteen people have been arrested so far in the case, including the sacked head of Sanlu Group, and dozens have been detained for questioning, according to state media.

Sanlu began receiving customer complaints about its milk powder as long ago as last December, Xinhua said.

China has said it also found melamine in nearly 10 per cent of milk and drinking yoghurt samples from three major dairy companies: Mengniu Dairy, the Inner Mongolia Yili Industrial Group and the Bright Dairy group.

Shares in Mengniu Dairy plunged nearly two-thirds to a 33-month low on Tuesday after brokers downgraded the stock on concerns the scandal will dent industry growth.

Shares in Inner Mongolia Yili Industrial Group were down 10 per cent at the lunch break in Shanghai and Bright Dairy group was down 7.8 per cent.