BEIJING - A second lawsuit has been filed against a Chinese dairy company at the heart of the tainted milk crisis, an attorney said Friday, as more than 10,000 children remained hospitalized after drinking milk powder laced with an industrial chemical.

Zhang Xiuwen, a migrant worker from southern Guangdong province, sued Sanlu Group Co., after his 11-month-old son was diagnosed with kidney stones, his lawyer Chen Beiyuan said. The baby had been fed formula produced by the company since birth.

The Guangzhou Intermediate People's Court has yet to accept the lawsuit, which seeks $132,000 in compensation, Chen said in a telephone interview. He said he was also planning to sue the Dairy Association in China for failing to supervise its members.

Although product liability lawsuits have become more common in recent years, lawyers advising the families of children sickened in the scandal said this week they face growing pressure from government officials to withdraw from the cases.

The milk powder, laced with the chemical melamine, has been blamed for causing the deaths of four infants and sickening more than 54,000 others.

Chinese dairy suppliers have been accused of adding melamine - used in plastics, paint and adhesives - to watered-down milk to make the product appear rich in protein and fool quality control tests.

The practice was apparently widespread in the industry, with government investigations showing that 37 Chinese dairy companies, including its most reputable brands, had tainted dairy products.

Eight of 10,666 children hospitalized are in serious condition after drinking the contaminated powder, which can lead to kidney stones and life-threatening kidney failure, the Health Ministry said this week.

Earlier this month, parents from central Henan province filed the first known lawsuit against Sanlu, seeking $22,000 in compensation for medical, travel and other expenses incurred after their 14-month-old baby developed kidney stones. The infant remains hospitalized.

The court in Zhenping county has also not yet decided whether to accept that case.

The government has been struggling to show the public that it is dealing successfully with the scandal but controls have also been imposed on media coverage of the crisis.

The scandal has sparked global concern about Chinese food imports, with more than 30 countries restricting Chinese dairy products, and in some cases all Chinese food imports. Recalls have also occurred in several countries of Chinese-made milk powders, biscuits and candies.

This week, the Health Ministry released guidelines on permissible levels of melamine in food. The chemical is now limited to one part per million for infant formula and 2.5 parts per million for liquid milk, milk powder and food products that contain more than 15 per cent milk.

There had been no previous standards for the amount of the chemical allowed in food products.

Wang Xuening, a ministry official, said small amounts of melamine can leach from the environment and packaging into milk and other foods but that deliberate tainting was explicitly forbidden.

Levels of melamine discovered in batches of milk powder recently registered as much as 6,196 parts per million.

New Zealand dairy giant Fonterra Group, which has a 43 per cent stake in Sanlu, announced Friday it will spend $5 million to fund a Chinese charity to establish a health care program for mothers and babies in poor rural areas of China.

Meanwhile on Friday, Myanmar state media reported nine brands of milk and infant powder imported into the country have been tainted with melamine.

The New Light of Myanmar reported that among the 16 brands of milk and milk powder tested, nine contain melamine. Authorities had banned the import of all dairy products from China and have begun tests on milk products sold in the country.