The health committee of the city of Bayan Nur issued the third-level alert, the second lowest in a four-level system.

The alert forbids the hunting and eating of animals that could carry plague and asks the public to report any suspected cases of plague or fever with no clear causes, and to report any sick or dead marmots.

Sunday’s warning follows four reported cases of plague in people from Inner Mongolia last November, including two of pneumonic plague, a deadlier variant of plague.

The bubonic plague, known as the “Black Death” in the Middle Ages, is a highly infectious and often fatal disease that is spread mostly by rodents.