North Korea confirmed its first coronavirus infections of the pandemic after holding for more than two years to a widely doubted claim of a perfect record keeping out the virus that has spread to nearly every place in the world.
The Korean Central News Agency said tests of samples collected on Sunday from an unspecified number of people with fevers in the capital, Pyongyang, confirmed they were infected with the Omicron variant.
"There has been the biggest emergency incident in the country, with a hole in our emergency quarantine front, that has been kept safely over the past two years and three months since February 2020," KCNA said.
In response, leader Kim Jong-un on Thursday called for a thorough lockdown of cities and counties and said workplaces should be isolated by units to block the virus from spreading.
The country's population of 26 million is believed to be mostly unvaccinated after its government shunned vaccines offered by the UN-backed COVAX distribution program, possibly because those have international monitoring requirements.
Kim during a ruling party politburo meeting called for officials to stabilise transmissions and eliminate the infection source as fast as possible, while also easing the inconveniences to the public caused by the virus controls.
Kim said "single-minded public unity is the most powerful guarantee that can win in this anti-pandemic fight", KCNA said.
Despite the decision to elevate anti-virus steps, Kim ordered officials to push ahead with scheduled construction, agricultural development and other state projects while bolstering the country's defence postures to avoid any security vacuum.
North Korea's announcement came after NK News, a North Korea-focused news site, cited unidentified sources who said authorities had imposed a lockdown on Pyongyang residents. South Korea's government said it could not confirm the report.
It is not immediately clear how large the North's outbreak is. Leif-Eric Easley, a professor of international studies at Seoul's Ewha Womans University, said the North would likely double down on lockdowns, even though the failure of China's "zero-COVID" approach suggests that does not work against the fast-moving Omicron variant.
"For Pyongyang to publicly admit Omicron cases, the public health situation must be serious," Easley said.
"This does not mean North Korea is suddenly going to be open to humanitarian assistance and take a more conciliatory line toward Washington and Seoul. But the Kim regime's domestic audience may be less interested in nuclear or missile tests when the urgent threat involves coronavirus rather than a foreign military."
Experts say a major COVID-19 outbreak would be devastating in North Korea because of the poor health system and could possibly trigger instability when combined with other problems such as serious food shortages.