BEIJING - Premier Wen Jiabao said the Chinese government was partly responsible for the tainted milk scandal that has sickened tens of thousands of children and shaken consumer confidence in the country's food exports.

In an interview published in this week's Science Magazine, Wen said the government feels "great sorrow" over the tainting, which has been blamed for the deaths of four babies.

"We feel that although problems occurred at the company, the government also has a responsibility," Wen said in the Sept. 20 interview posted Friday on the Web site of the American Association for the Advancement of Science journal.

A Chinese version of the interview in the People's Daily newspaper, the ruling Communist Party's mouthpiece, also quoted Wen as saying the government had been lax in "supervision and management."

It's a rare admission by a member of China's leadership. Wen has won popular admiration for his visits to the country's poor rural areas and victims of the devastating May 12 earthquake in Sichuan province.

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

Melamine is used in the manufacturing of plastics, fertilizer, paint and adhesives. Health experts say ingesting a small amount poses no danger, but in larger doses, the chemical can cause kidney stones and lead to kidney failure. Infants are particularly vulnerable.

Wen said the process of making milk products - from the collection of raw milk to the production and transportation - "all need to have clear standards and testing requirements and corresponding responsibilities."

"I once again solemnly emphasize that it is absolutely impermissible to sacrifice people's lives and health in exchange for temporary economic development," Wen said. "Food, all food, must meet international standards."

In its efforts to deal with health and public relations issues stemming from the situation, the government has issued strict standards for allowable melamine levels in food and 5,000 of its inspectors have been dispatched to provide 24-hour supervision over the industry.

A number of officials have been fired for negligence and some of China's dairy giants ensnared in the turmoil have opened their factories to a government-led media tour in a bid to regain the public's trust.

The General Administration of Quality Supervision, Inspection and Quarantine, the country's chief quality watchdog, said on its Web site Saturday that a fresh round of random tests on liquid milk have showed allowable amounts of melamine.

The agency said it collected samples from 544 batches of liquid milk from 70 brands in 22 cities, including Beijing, Shanghai, Chongqing and Harbin.

"All the samples were found to be in line with melamine limits," the agency said.

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

China's exports were hammered by quality scandals even before the uproar over contaminated milk. Its manufacturing industry had been under intense scrutiny after melamine and other industrial toxins were found last year in exports ranging from toothpaste to a pet food ingredient.

Since the latest scare, milk-linked products from China have been withdrawn from stores in dozens of countries as governments increase vigilance and step up safety tests.

Panama on Friday said several Chinese cookies and candy taken out of stores have tested positive for traces of melamine.

Panama's Food Safety director Gilberto Real said of 56 Chinese products pulled from stores last month, 28 tested negative and 24 are still being examined.

Dozens of Panamanians died last year after taking Chinese-made medicine contaminated with a thickening agent found in antifreeze.