Yili, Mengniu and Guangming - big brands consumed by millions of Chinese - were affected by the recall after the authorities checked their products and found traces of melamine, a chemical used in plastics.

'All problem products have been banned from our stores,' said an executive at Jian-Mart, a popular supermarket chain.

'Products from Yili, Mengniu and Guangming have been pulled off the shelves, including milk, milk powder and yoghurt,' she said, giving only her surname, Zhao.

The government agency in charge of product quality supervision yesterday issued detailed findings from a comprehensive national check, showing 24 of the 295 batches it tested from the three dairy companies were contaminated.

'The manufacturers should, of their own accord, recall all products where melamine has been detected,' the General Administration of Quality Supervision, Inspection and Quarantine said on its website.

Melamine can make products look like they have high levels of protein, but it can be lethal if consumed in large amounts.

Four babies in China have died so far from kidney failure, and more than 6,000 have developed kidney stones.

The scare escalated on Thursday when the government announced that a number of milk products, not just baby formula, were tainted with the chemical.

Retailers complained that the scandal was costing them dearly.

'Normally we can sell 53,000 yuan (S$11,100) of dairy products per day, but at present, we sell less than 10,000 yuan,' said Mr Wang Feiqi, a manager at a branch of supermarket chain Wu-Mart.

'I think this will last at least one or two months. Customers won't come to buy these products unless they reach the national standard.'

Reactions to the Chinese recall were immediate, with major Hong Kong supermarket chains ParknShop and Wellcome removing all Mengniu liquid milk from their shelves.

A day earlier, Hong Kong recalled products made by Yili. Products by Guangming are not sold at ParknShop and Wellcome.

Hong Kong is set to introduce a law against excess melamine in food. Mr York Chow, Hong Kong's Secretary for Health, Environment and Food, told legislators yesterday: 'We are preparing to legislate against melamine in food. The administration is expeditiously studying the standards laid down by the European Union, the US Food and Drug Administration, and other international bodies.'

Yesterday, Starbucks in mainland China also stopped serving drinks with milk as its outlets pulled milk supplied by Mengniu.

Starbucks' decision affected two-thirds of its 330 stores in China, Shanghai-based Starbucks spokesman Caren Li said.

Separately, South Korea has detected melamine in fish feed manufactured from squid caught domestically and in China, officials said yesterday. Investigators found traces in feed made by a South Korean company, said the country's Ministry for Food, Agriculture, Forestry and Fisheries.

AGENCE FRANCE-PRESSE, REUTERS