BEIJING Chinas 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 Chinas milk powder and liquid milk produced before Sept. 14 was ordered pulled off the shelves to be tested by manufacturers, Chinas 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.

The scandal has 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, Chinas 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.

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.