The country said that it had locked down the area and mobilized medical teams after four fever cases were reported from Ryanggang Province, but that it was not COVID-19, over which the country declared victory this month.
"It was revealed that all of the fever patients in the Ryanggang Province were patients with the flu," KCNA news agency reported on Friday, saying experts conducted clinical symptoms observation, epidemiological relationship investigation and nucleic acid tests.
North Korea has never confirmed how many people caught COVID-19, apparently lacking the means to conduct widespread testing.
Instead, it reported daily numbers of patients with fever, which totaled some 4.77 million, and said there have not been any new such cases since July 29.
In a separate dispatch, KCNA carried a Russian state media interview with Moscow's ambassador to North Korea, Alexandr Matsegora, detailing the COVID situation in the isolated country.
Matsegora said he had raised the possibility that the virus had come from China, rather than through anti-North leaflets flown from South Korea as Pyongyang argued.
But North Koreans dismissed that view, presenting him data that showed the northern regions bordering China were much less affected by the outbreak than the southern areas, he said, without providing numbers.
Reuters was unable to verify North Korea or Matsegora's assertions, and most foreign embassies and international agencies have left the country because of the pandemic.
Seoul's Unification Ministry, which handles cross-border ties, has denied Pyongyang's claim as groundless, and said Friday that a resurgence of COVID cannot be ruled out in the North.
Matsegora expressed concerns over escalation between the two Koreas, with the North vowing "deadly retaliation" over the leaflet-sending activity in the South, which he said Pyongyang "compared with the use of biochemical weapon."
"The situation on the Korean peninsula will be further aggravated with the issue of COVID-19 as a momentum," he said.
NK News, a website specializing in North Korea, reported Thursday that the country might be preparing to reopen the border in the near future, citing several unnamed sources, though similar reports have proved premature in the past. (NS/VOA)