China’s deadly pig virus outbreak could spread to other Asian countries at any time, a United Nations agency has warned.

The UN Food and Agriculture Organisation raised concerns on Tuesday as China, the world’s largest pork producer, scrambled to contain an outbreak of African swine fever.

More than 24,000 pigs have been culled in four provinces since the first reported incidence in the northeast province of Liaoning in early August.

Last week, the eastern city of Lianyungang culled 14,500 pigs in an attempt to check the disease’s spread.

In a statement the FAO said the cases had been detected in areas more than 1,000km (600 miles) apart, meaning the disease could cross national borders.

The “diverse geographical spread of the outbreaks in China have raised fears that the disease will move across borders to neighbouring countries of Southeast Asia or the Korean Peninsula where trade and consumption of pork products are also high”, the FAO said.

“The movement of pig products can spread diseases quickly and, as in this case of African swine fever, it’s likely that the movement of such products, rather than live pigs, has caused the spread of the virus to other parts of China,” said Juan Lubroth, FAO’s chief veterinarian.

African swine fever is not harmful to humans but causes haemorrhagic fever in domesticated pigs and wild boar that almost always ends in death within a few days.

There is no antidote or vaccine, and the only known method to prevent the disease from spreading is a mass cull of the infected livestock.

In a report to the World Organisation for Animal Health, Beijing said an emergency plan had been launched and control measures taken to halt the spread of the disease.

The FAO warned in May of the risk of the spread of African swine fever from Russia.

Around half of the world’s pigs are raised in China, and the Chinese are the biggest consumers of pork per capita, according to the FAO.