“Our recent campaign has achieved notable success. But this is just the beginning,” an unnamed official from the cabinet’s food safety task force told Xinhua news agency.

“The campaign should not be given an excessively high appraisal. We cannot lower our guard or rest up, and must be aware of the complex, long-term nature of the food safety problem and remain on high alert,” the official added.

“We must keep up the pressure and must not give criminal elements any opportunities.”

China has struggled to rein in health safety violations in the unruly and vast food sector despite harsh punishments and repeated vows to deal with the problem.

Since July, Chinese courts have sentenced at least a dozen people to jail, including one person who received a suspended death sentence, for their roles in producing or selling pork tainted with toxic chemicals.

In the latest scandal, authorities detained 32 people for making and selling tons of cooking oil dredged from gutters and repackaged for sale as new.

In 2008, at least six children died and nearly 300,000 fell ill from drinking milk made laced with melamine powder, an industrial compound added to milk to give misleadingly high results in protein tests.