The nation is on alert after cats were found infected with the avian influenza (AI).

According to the Ministry of Agriculture, Food and Rural Affairs and the Korea Centers for Disease Control and Prevention, one house cat and another stray cat were found dead earlier this week in Pocheon, Gyeonggi Province.

This is the first time the AI infection was found in mammals since an infection was reported in a dog last year.

An official at the Centers for Disease Control has said there have been cases of cats being infected with AI. But the official stressed that there has been no incident worldwide of a cat infected with the H5 strain of AI spreading the virus to a human.

A professor of veterinary medicine at Chungbuk National University also said the AI can be passed on to cats as well as people but there has been no precedent of cats spreading the virus to humans. The professor said that likelihood is very low.

A ministry official also said it is very unlikely the AI will spread further because of the infection of cats. But he said the government will nonetheless step up existing quarantine measures to prevent wild animals including rats from entering poultry farms such as installing nets and hunting down rats.