Ten people have been arrested and more than 100 companies closed down as officials continue their crackdown on the use of banned animal drugs and toxic pesticides in farm produce.

Agricultural safety inspections have been stepped up to guarantee food quality, a senior agricultural official said on Monday.

Gao Hongbin, vice-minister of agriculture, added that all agricultural wholesale markets in large and medium cities will be under surveillance by the end of the year.

So far, 479 out of the 676 markets nationwide are covered.

Gao said the ministry also hoped to eliminate the use of forbidden pesticides and banned animal drugs in the four-month campaign.

"What we seek is a system that will continuously improve the quality of agricultural products," he told a press conference organized by the State Council Information Office.

An accountability system, detailed inspection records and a reliable way of tracing agricultural products are all needed, he said.

Gao said that 93 percent of the country's vegetables are safe in terms of pesticide residue and more than 98 percent of meat products are up to scratch concerning the remains of clenobuterol hydrochloride, which is a drug some farmers used to feed pigs. It has been abolished due to side effects to human heart.

Officials also rebuffed claims that China has suppressed the true extent of the latest blue-ear disease outbreak.

Li Jinxiang, deputy director of the veterinary bureau of the ministry, dismissed allegations that China is hiding the spread of the disease and that pigs in Myanmar and Vietnam had been infected.

The government has strict regulations on the reporting of disease, Li said.

"Anyone caught hiding the truth about the spread of the disease will be punished," he promised, adding that the government has provided relevant international bodies, including the Food and Agriculture Organization and World Organization for Animal Health, with all the information it had on the disease.

Li added that he had not yet had official confirmation of outbreaks in Myanmar and Vietnam.

"It is groundless to say the outbreak in China has spread to other countries," he said.

Li pointed out that blue-ear disease was first identified in the United States in 1987 and that DNA from the outbreak in China showed it was more than 90 percent identical to the US strain. Chinese farms have fallen victim to a foreign disease, he said.

The outbreak has so far claimed the lives of about 290,000 pigs.

Li added that a recent outbreak of bird flu in Panyu, Guangdong Province, has been brought under control, although experts were not yet ready to lift the quarantine of the area.

The large number of dead ducklings discovered in the area were confirmed to have been killed by bird flu on September 17, since then more than 100,000 birds have been culled.