Chinese authorities are warning that wind might be blowing COVID-19 into the country from North Korea

• A Chinese city's officials are concerned that the wind may be blowing in Covid from North Korea.
• Authorities in the city can't figure out where their infections are coming from, Bloomberg reported.

Authorities in the Chinese city of Dandong, which sits on the border with North Korea, have indicated that they suspect winds have swept COVID-19 into their city from their ailing neighbor.

According to the local pro-government outlet Global Times, Dandong is currently facing a spike in daily coronavirus cases, and the border city has periodically locked down residential complexes since April.

However, city officials have been unable to establish a chain of transmission for the spread, nor have they determined how the virus is entering the city, Bloomberg first reported.

One potential answer they've reached is that the wind may be blowing the virus into residents' homes from epidemic-stricken North Korea. According to NK News, Kim Jong Un's regime has recorded more than 4.2 million "fever cases" — likely to be COVID-19 cases that the country can't confirm due to a lack of testing kits,

In an online notice published on May 31, Dandong authorities urged residents to keep their windows open for ventilation and close them if one lives along the Yalu border river and there are southerly winds blowing.

The new advisory is a step up from China's previous promotion of a "cold chain theory," which suggested that COVID-19 first arrived in China via imported frozen food. The World Health Organization has since refuted the theory.

There's currently no scientific evidence that shows COVID-19 can spread over long distances through the air. According to the US Centers for Disease and Control and Prevention, the risk of transmission is highest when one is at a distance of three to six feet from an infected person.