At least five people are still reported as missing after the disaster.
The initial tremor happened at around 23:45 GMT on Sunday and reportedly lasted for over a minute. The Chinese seismological bureau initially measured the quake at magnitude 6.6. The first tremor was followed by a series of quakes, including a magnitude 5.6 jolt at 01:12 GMT.
The quake hit near the city of Dingxi in Gansu province, one of the least populated in the whole country. However, the Dingxi area has a great concentration of farms and towns. The earthquake was also felt in neighboring cities of Longnan, Tianshui, and the provincial capital city of Lanzhou.
The China Earthquake Administration is closely monitoring the seismic situation in the region and has sent disaster relief teams to the scene.
Authorities dispatched troops, police officers and local militia to the affected area to assist in rescue operations, reports Xinhua news agency.
On April 20 this year, China was struck by the worst earthquake in three years that killed at least 157 people and left around 5,700 injured, according to the Ministry of Civil Affairs. The magnitude 6.6 quake shook a remote mountainous area of south-western China’s Sichuan province, close to where an earthquake killed almost 70,000 people in 2008.