BEIJING (AP) -- China is ordering all liquid and powdered milk manufactured before Sept. 14 to be taken off the shelves for melamine testing, a news report said Tuesday, the first time Beijing has issued a blanket recall of products since the tainted dairy scandal broke last month.

It is the latest in a series of measures China has taken to allay worries over the quality of Chinese products and restore consumer confidence since four babies died and tens of thousands of children were sickened after drinking tainted milk.

Authorities have blamed dairy suppliers for the crisis, saying they added the industrial chemical 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 life-threatening kidney failure.

Citing a notice jointly approved by six government ministries and administrations, the official Xinhua News Agency said Tuesday that all milk powder and liquid milk produced before Sept. 14 must be subject to testing nationwide by manufacturers.

"Regardless of the brand or the batch, they must be taken off shelves, their sale must be stopped," Xinhua said.

The notice said the products will be sold again only after they pass quality tests and are labeled as safe. The Xinhua report did not give any other details or say why the recall was being implemented now.

Only some types of milk powder and milk have been recalled in mainland China so far. On Sept. 16, a recall list was issued for 69 batches of milk powder made by 22 companies. Another recall list was released on Sept. 19 for liquid milk.

It is also not clear why the cut off date for the latest notice is Sept. 14, but China launched a countrywide inspection of dairy producing facilities focusing on milk collecting centers on Sept. 15.

According to the Xinhua report, the government agencies involved were the Health Ministry, the Commerce Ministry, the Ministry of Information and Industry, the Administration for Industry and Commerce, the State Food and Drug Administration and the General Administration of Quality Supervision, Inspection and Quarantine, the country's chief quality watchdog.

Officials at the various ministries and administrations said AQSIQ had drafted the notice and was the only one authorized to answer questions.

Telephones at the agency rang unanswered on Tuesday and officials did not respond to a faxed request for information. The notice was not posted on the AQSIQ Web site.

The crisis -- which has spread overseas with Chinese milk products pulled out of stores in dozens of countries -- has forced the government to fire local and even high-level officials for negligence, and make repeated promises to raise product safety standards.

Last week, the Health Ministry issued guidelines limiting acceptable melamine levels in milk and food products. There had been no previous standards for the amount of the chemical allowed.

Health officials said deliberate tainting is explicitly forbidden but acknowledged that small amounts of melamine can leach from the environment and packaging into milk and other foods.

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

The measures increase punishments for those caught violating safety standards.

On Monday, the AQSIQ said that the latest tests on 172 batches of milk powder from 55 different brands showed them to be safe for melamine content.

So far, 1,300 batches of milk powder from 195 different brands produced after Sept. 14 have shown no signs of contamination, it said.

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