The earthquake occurred in the sparsely-populated pastoral areas, where brick and wood bungalows are mostly scattered, rescuers said.

The barns and sheep pens of the local residents were damaged to a large extent, said Doter, Party secretary of the county's Huanghe Township.

At an average altitude of 4,200 meters, Maduo County is located at the source region of the Yellow River with a great number of rivers and lakes.

In the past five years, about 25 earthquakes of magnitude 3 or above have occurred within 200 kilometers of the epicenter, the largest of which occured Saturday, CENC data showed.