BEIJING – China's store shelves are being cleared of all milk and milk powder more than a month old, a huge recall that marks the latest government effort to restore consumer confidence after four babies died from drinking milk tainted with an industrial chemical.

In Hong Kong, authorities announced that another child has developed kidney stones after consuming contaminated products, bringing to eight the number of children in the territory sickened by Chinese dairy.

All of mainland China's milk powder and liquid milk produced before Sept. 14 was ordered pulled off the shelves to be tested by manufacturers, China's official Xinhua News Agency said.

“Regardless of the brand or the batch, they must be taken off shelves, their sale must be stopped,” Xinhua said, citing a notice issued by six government ministries and administrations.

It was the first time the government has issued a blanket recall of products since the tainted milk scandal began.

The notice said the products will be sold only after they pass quality tests and are labeled as safe. Those that fail checks must be reported to the ministries, recalled and sealed off from consumption, it said. The notice did not say why the recall was being implemented now.

China launched a countrywide inspection of dairy producing facilities focusing on milk collecting centers on Sept. 15 – leaving open the possibility that some milk products more than a month old have yet to be scrutinized.

The notice was issued by China's chief quality watchdog, the General Administration of Quality Supervision, Inspection and Quarantine in conjunction with five other central government ministries and administrations. Telephones at the General Administration rang unanswered Tuesday and officials did not respond to a faxed request for information.

Four babies died and tens of thousands of children have been sickened by milk spiked with the melamine, a nitrogen-rich chemical used to make plastics and fertilizers.

The scandal prompted the Chinese Health Ministry to issue guidelines limiting acceptable melamine levels in milk and food products. There were no such standards previously.

The State Council, China's Cabinet, has also tightened regulations for the dairy industry, mandating stricter controls over cattle breeding, the purchase of raw milk and the production and sale of dairy products.

Authorities have blamed dairy suppliers for the crisis, saying they added melamine to watered-down milk to fool quality control tests and make the product appear rich in protein.

Melamine can cause kidney stones as the body tries to eliminate it and, in extreme cases, lead to kidney failure.

The crisis has spread overseas with Chinese milk products pulled out of stores in dozens of countries as governments increase vigilance and step up safety tests.

On Tuesday, Hong Kong's government said a 2 1/2-year-old boy developed two kidney stones after consuming melamine-laced milk and cookies. He did not show any signs of renal problems or require hospitalization.

Over the past two years, the boy had regularly consumed milk from the Chinese dairy Yili Industrial Group Co. and eaten chocolate-filled Koala cookies made by Tokyo-based snack maker Lotte Group, said government spokesman Alex Cheng. Samples of Koala cookies in Hong Kong and Yili milk in China have tested positive for melamine.

In Thailand, the bakery chain S&P recalled all its packaged cookies nationwide as a precaution after Swiss authorities said they found high concentrations of melamine in the products.

Swiss authorities said Monday tests of the confection found high melamine levels.

Witoon Sila-on, a vice president at S&P Syndicate PCL, said the company had never exported its cookies to Switzerland and questioned where the sample came from. Witoon also said the cookies in question included milk powder imported from Australia – not milk powder from China.

Associated Press Writer Dikky Sinn in Hong Kong contributed to the report.