Recent outbreaks of African swine fever in China have not caused a big impact on the supply and price of pork in China, according to the Ministry of Agriculture and Rural Affairs.

The rise in the price of pork in the third quarter this year, like previous years, was partly due to the Mid-Autumn Festival that fell on Sept 24 and the seven-day National Day holiday, said Tang Ke, chief for market and information at the ministry, at a news conference on Friday.

The average wholesale price of pork in China was 19.99 yuan ($2.90) per kilogram in September, a rise of 4.8 percent over August, and 15.2 percent over July. The price in September was 2.4 percent lower than September last year, he said.

Between Oct 1 and Oct 7, the average wholesale price of pork was 20.04 yuan, 0.5 percent lower than the level of the first week of September, Tang said.

"Following outbreaks of African swine fever in August, we have intensified surveillance of the operation of the pork market and taken measures in response to ensure supply," he said. "As a whole, the impact on pork production was limited."

However, different areas have seen different price changes since August, as the disease outbreaks have interrupted the transport of pigs and pork. In places where outbreaks occurred, such as Liaoning province, the price of pork saw a bigger decline due to a surplus of pigs, as they were not allowed to be transported to other areas, Tang said.

In places such as Beijing, Shanghai and Zhejiang, which traditionally rely on pork imported from other areas, pork prices have increased by a bigger margin, he said.

More than 30 outbreaks of African swine fever had occurred in China by Wednesday, since the first case in China was reported in Shenyang, Liaoning province, on Aug 1.

The latest one occurred in Datong, Shanxi province, on Wednesday, where seven pigs raised by a farmer were infected with the disease, including four dead, according to the Ministry of Agriculture and Rural Affairs.

Local authorities immediately responded with measures such as slaughtering all infected pigs and carrying out quarantine measures in the vicinity, including banning the transport of all pigs and pork out of the area, the ministry said, adding the disease has been effectively controlled.

African swine fever is deadly to pigs but does not affect humans.

Zhu Zengyong, an industry researcher at the Chinese Academy of Agricultural Sciences, said some places hit by the outbreaks have seen pork prices slump by about a half.

In Liaoning province, for example, the price of pork has been reduced to about 8 yuan a kilogram, lower than the cost of raising them, he said.

"The problem is that pigs and pork in these areas cannot be transported to other areas for sale, due to the disease," he said. "Slaughtering companies have taken advantage and kept lowering prices for pig farmers."

In Beijing, the supply of pork is primarily from neighboring areas such as Hebei province, and its market is stable, he said.

Tang, from the Ministry of Agriculture and Rural Affairs, said pork prices in China in general will continue to decrease in the near future, but prices may see a small increase ahead of the Spring Festival, which falls in early February.