Four people were injured after a 6.9-magnitude earthquake rattled Menyuan County in northwest China's Qinghai Province on Saturday, followed by some minor jolts on the day. 

The quake caused damages to multiple highways in Qinghai's provincial capital Xining and the suspension of a 1,776-km high-speed railway running through the region.

Bullet trains temporarily suspended operations on the Lanzhou-Urumqi high-speed railway due to damages, some severe, to some rail sections.

The slightly injured people were back to their homes after treatment, according to local authorities at a press conference at noon.

After the quake, the province has activated a Level II emergency response, the second highest in China's four-tier earthquake emergency response system, according to the provincial department of emergency management.

Some houses were found damaged or partially collapsed as firefighters and fire engines rushed to the scene, according to the China Media Group.

The earthquake jolted a sparsely-populated area at 1:45 a.m., with a depth of 10 kilometers at the epicenter, according to the China Earthquake Networks Center (CENC).

Provincial earthquake administration has mobilized a strong rescue team with devices, fire fighters, sniffer dogs and relief materials to be dispatched to the affected areas.