The post made no mention of Covid-19 but said city residents should stay at home until the end of Sunday and submit to temperature checks several times a day, according to NK News, which monitors North Korea.
On Tuesday, the website reported that residents of Pyongyang appeared to be stocking up on goods in anticipation of stricter measures. It is unclear whether other parts of the country have imposed new lockdowns.
North Korea acknowledged its first outbreak of Covid-19 last year, but had declared victory over the virus in August.
The secretive country has never confirmed how many people have contracted Covid, apparently because it lacks the resources to conduct widespread testing.
Instead, it reported daily numbers of patients with fever, a number that rose to about 4.77 million, in a population of about 25 million. But since July 29, it has not reported such cases.
State media continued to report on anti-pandemic measures to combat respiratory illnesses, including influenza, but had yet to report on the lockdown order.
On Tuesday, state news agency KCNA said the city of Kaesong, near the border with South Korea, has stepped up public communication campaigns “so that all working people voluntarily comply with anti-epidemic regulations in their work and life.”