North Korean leader Kim Jong Un has placed a city near the border with South Korea under lockdown over concerns the country has its first coronavirus case, state media reported.

The measure was taken on Friday afternoon after a resident of Kaesong was found with suspected Covid-19 symptoms, according to North Korea’s Central News Agency (KCNA).

It added the person is a runaway who had fled to South Korea years ago before illegally crossing the border into the North early last week.

READ MORE: North Korea, the history, the fact and the fiction

If that person is officially declared a virus patient, he or she would be the North’s first confirmed coronavirus case with the country steadfastly saying it has no single virus case on its territory, a claim questioned by outside experts.

The news agency said respiratory secretion and blood tests showed the person “is suspected to have been infected” with the virus.

It said the suspected case and others who were in contact as well as those who have been to Kaesong in the last five days were placed under quarantine.

READ MORE: Kim Jong Un rumours spark succession speculation

Describing its anti-virus efforts as a “matter of national existence,” North Korea earlier this year shut down nearly all cross-border traffic, banned foreign tourists and mobilized health workers to quarantine anyone with symptoms.

Earlier this month, Mr Kim urged officials to stay alert over the coronavirus threat, warning that complacency risks “unimaginable and irretrievable crisis”.