Residents of one Heilongjiang city have been ordered into isolation while the city’s border with Russia is closed following a wave of imported coronavirus cases.

The city of Suifenhe is located on the far eastern end of Heilongjiang province and serves as a busy border crossing with the Russian city of Vladivostok located nearby.

This week, Heilongjiang has seen a spike in coronavirus cases, reporting 20 on Monday and 25 on Tuesday, all involving Chinese nationals returning home from Russia through Suifenhe.

While China has banned all foreigners from entry and significantly cut down on international flights, imported Covid-19 cases continue to trickle into the country. In this case, Chinese nationals living in Russia have been flying to Vladivostok and then crossing by land into China via Suifenhe.

The Chinese consulate in Vladivostok has now warned travelers that this avenue has been closed after Suifenhe’s medical system reached maximum capacity.

Meanwhile, residents of Suifenhe have told to isolate themselves at home, only coming out once every three days to buy groceries.

The order comes as Wuhan, the original epicenter of the coronavirus outbreak, ended its 76-day lockdown.

With domestic transmissions dropping to zero, China has shifted its attention towards infections coming in from abroad. So far, more than 1,000 imported coronavirus cases have been reported.

Concern is also growing about a potential second wave of the virus at the other end of the country in Guangzhou where risk alerts have been raised after some Nigerian residents transmitted the virus to a local restaurant owner and her kid.