China is facing a new coronavirus flare-up along its remote northern border with Russia, far from the epicenter of Wuhan, where it is close to declaring victory in the battle against the pandemic.

The northern frontier has been sealed and emergency medical units have been rushed to the area to fend off the threat from people bringing the virus back from abroad.

The long, porous border of sprawling Heilongjiang province and neighboring Inner Mongolia has much less travel than major cities like Beijing and Shanghai. But it is a popular alternative route into the country.

Many Chinese live and work in Russia, where China has major investments encouraged by warm ties between Beijing and Moscow.