Beijing city said individuals who recently visited overland ports of entry on China's borders should avoid the Chinese capital, with national authorities concerned over the risk of Covid transmission from abroad as they battle a month-long outbreak.

The small northern administrative divisions of Heihe, Erenhot and Ejina, along China's borders with Russia and Mongolia, were among the hardest-hit areas in a nationwide outbreak since mid-October that resulted in more than 1,200 domestically transmitted cases showing confirmed symptoms, according to Reuters.

Although China's infection numbers are lower than in many other countries and a dozen provincial regions have already brought the recent flare-up under control, it is pursuing a zero-tolerance policy against local clusters with stringent measures along international borders and other areas at higher risk for transmission.