BEIJING (Reuters) – China reported a new case of African swine fever in Xuancheng in Anhui province on Monday, the second in the city in as many days, raising the risk for farmers as the disease spreads rapidly in the world’s top pork producer.

The new outbreak, the seventh in China since early August and the third in the eastern province of Anhui, occurred on a small farm of 308 pigs, killing 83 of them, said the nation’s agriculture ministry.

The highly contagious disease was also found on another small farm in Xuancheng on Sunday.

“It looks like it’s accelerating,” said Pan Chenjun, senior analyst at Rabobank, adding that she expected farmers to start selling off pigs before they are forced to cull animals if the disease hits their own or neighboring farms.

“I think in coming days they will liquidate their herds,” she said. That would hurt prices for all farmers, even those able to keep the disease at bay.

China has now discovered seven cases of the deadly disease in five provinces: in Liaoning in the country’s northeast, in central China’s Henan, and in the eastern provinces of Anhui, Jiangsu and Zhejiang.

China’s agriculture ministry said on Sunday it will shut live hog markets in the affected provinces. It also imposed a ban on transporting pigs and pork products from the provinces, the most drastic measure taken so far, and one set to have major repercussions across the supply chain.

The prohibition will effectively prevent slaughterhouses and meat processing factories from using pigs or pork from affected regions. Stopping pigs and pork products from being transported out of those regions will also cause major disruption to farmers, traders and slaughterhouses.

“This will be a very serious situation for large companies with several farms in the northeast,” said Pan.

Northeastern provinces do not have sufficient slaughterhouse capacity and typically transport pigs to provinces in the south.

In Henan province, one of China’s top pig-producing regions, animal stocks have jumped because farmers there can no longer sell animals to other parts of the country, said an agent surnamed Ni who trucks pigs around the province.

“I haven’t had any business in the past two days because there are too many pigs in the market. Prices are bad and there is not much demand,” he said. Ni said he used to transport up to 700 pigs a day, but current volumes are around 700 a week.

The government also said live hogs from unaffected provinces cannot be transported through those that have reported infections.

Until now, authorities had only stopped transportation of pigs and products and shut live markets in and around infected areas.

“Costs will go up and it will take much longer to get pigs to the consumption areas,” said Ni.

Shares in meat processor Shandong Longda Meatstuff Co Ltd fell more than 7 percent on Monday morning to 6.7 yuan, before recovering later in the day.

Major feed and pig farming firm Beijing Dabeinong Technology Group Co Ltd fell by 2.1 percent, while New Hope Liuhe Co Ltd fell 1.5 percent in morning trade before rebounding.

Xuancheng city is around 70 km (45 miles) southeast of Wuhu city, where another African swine fever case was reported last week.

The ministry said it had culled more than 38,000 hogs as of Sept. 1 as it tries to contain the outbreak.

Last week, the government warned it cannot rule out the possibility of new outbreaks, highlighting the challenge for the government in controlling the disease.

The virus is transmitted by ticks and direct contact between animals, and can also travel via contaminated food, animal feed and people moving from one place to another. There is no vaccine for the disease, but it is not harmful to humans.

(Reporting by Judy Hua, Stella Qiu, Hallie Gu, Josephine Mason and Dominique Patton; Editing by Richard Pullin and Tom Hogue)