SEOUL (Reuters): North Korea reported its first COVID-19 outbreak on Thursday, calling it the “gravest national emergency” and ordering a national lockdown, with state media saying an Omicron variant had been detected in the capital, Pyongyang.

North Korea had never confirmed a COVID infection before Thursday although South Korean and U.S. officials have said there could have been earlier cases in the isolated country, given its trade and travel with China before it sealed its border to block the virus in early 2020.

“The state’s most serious emergency has occurred: A break emerged in our emergency epidemic prevention front that had been firmly defended until now,” the official KCNA news agency said.

The first public admission of COVID infections highlights the potential for a major crisis in a country that lacks medical resources and has refused international help with vaccinations and kept its borders shut.

As of March, not only had no cases of COVID been reported, according to the World Health Organization (WHO), but there was no official record of any North Koreans being vaccinated.

KCNA said that samples taken on May 8 from people in Pyongyang who were experiencing fevers showed a sub-variant of the Omicron virus, also known as BA.2. It did not give the number of cases or say what the source might have been.

Earlier on Thursday, Chinese state television reported North Korea has imposed a stay-at-home order since Tuesday citing “suspected flu symptoms” among some people.

North Korean leader Kim Jong Un convened a meeting of the ruling Workers’ Party’s powerful politburo, ordering a “strict lockdown” nationwide and the mobilisation of emergency reserve medical supplies.

“The state epidemic prevention work shall be switched over to the maximum emergency epidemic prevention system,” KCNA said.

State television showed Kim wearing a mask upon arrival for the meeting, before taking it off as it began. All other attendees wore masks.

In past footage of such meetings, everyone but him wore a mask. There was no sign of masks in pictures of a recent big military parade. Click here to read more.