North Korea has claimed that the four new fever cases reported on Tuesday were in fact cases of the flu.

Quoting the nation's state emergency epidemic prevention headquarters, the North's official Korean Central News Agency(KCNA) said on Friday that the four fever-afflicted patients in Ryanggang Province all had influenza.

The KCNA said the health authorities confirmed the influenza diagnosis after monitoring their clinical symptoms and conducting epidemiological surveys and nucleic acid tests.

It added that the body temperatures of the fever patients returned to normal levels.

The KCNA said the emergency epidemic prevention headquarters ordered more thorough tests of fever cases and lifted the lockdown of the area.

On Thursday, North Korea said that four fever cases suspected of being an infection of a "malignant epidemic disease" were reported in the northern province two days earlier, two weeks after the country declared victory in the fight against COVID-19.