South Korea is on alert as an African swine fever virus gene was found in food products that a South Korean brought in from China.

The Ministry of Agriculture, Food and Rural Affairs said on Saturday that in a preliminary test, the gene was detected in dumplings and sausage declared by a South Korean tourist who was returning from Shenyang, where a case of the highly contagious animal disease in China was recently reported.

The ministry plans to conduct additional tests to confirm the detection by Monday.

African swine fever is known as the most dangerous swine disease because there is no effective vaccine or treatment.

Last week, the South Korean government issued an alert against the disease, following three outbreaks in China this month. The agriculture ministry asked local livestock breeders not to travel to affected regions in China, strengthen disinfection measures and take extra precautions when feeding food waste to pigs.