The government order comes a day after NK News, citing sources in Pyongyang, reported that people in the city appeared to be stocking up on goods in anticipation of a lockdown.

It is unclear if other areas have imposed similar lockdowns and state media has not announced any new measures.

Experts suggested that North Korea's largest city is likely dealing with the re-emergence of Covid.

"Covid is disappearing and reappearing depending on the temperature, not just in North Korea but around the world," said Go Myong-hyun, a researcher at the Asan Institute for Policy Studies.

The Korean peninsula is currently in the grip of what weather forecasters have described as a Siberian cold snap, with temperatures in Pyongyang dropping as low as -22 degrees Celsius (-7.6 Fahrenheit).

"It was quite premature for North Korea to celebrate its victory over the virus... with the drop in temperature, Covid has re-emerged," Go told AFP.

"North Korea must have prepared for it to some extent, but it seems that the virus reappeared a little sooner than they thought."

China trade

North Korea's neighbour and key trading partner China recently abandoned its zero-Covid policies, and battled a wave of infections that overwhelmed hospitals and crematoriums.

North Korea has maintained a rigid blockade since the start of the pandemic, but does allow some trade with China.

In May last year, North Korea officially acknowledged its first Covid outbreak but declared victory over the virus just three months later, calling it a "miracle".

Experts, including the World Health Organization, have long questioned Pyongyang's Covid statistics and claims to have brought the outbreak under control.

North Korea has one of the world's worst healthcare systems, with poorly equipped hospitals, few intensive care units and no Covid treatment drugs, experts say.

It is not believed to have vaccinated any of its 25 million people, although reports indicate it may have received some vaccines from China.