Local residents run out of buildings. [Photo/chinanews.com]

BEIJING -- An earthquake measuring 6.4 on the Richter scale hit Menyuan county of Haibei Tibetan Autonomous Prefecture in northwest China's Qinghai province at 1:13 a.m. on Thursday.

The epicenter was monitored at 37.68 degrees north latitude and 101.62 degrees east longitude, with a depth of 10 kilometers, according to the China Earthquake Networks Center (CENC).

An aftershock, measuring 3.4 on the Richter scale, was reported minutes after the initial quake.

Reports of casualties are not instantly available.

Menyuan is home to approximately 150,000 people. So far, telecom services in the country has remained normal.

"The tremor lasted one to two minutes... with a rumbling noise," said Ma Wulong, a local resident in Menyuan county.

"Everyone is out now," he told Xinhua over phone.

Li Zhanqing, deputy head of a forestry farm in Menyuan, said armed police and medical staff in the county have already been mobilized by the time he got to the downtown Menyuan.

Tremors are also felt in Xining, capital city of Qinghai Province, and in the neighboring Gansu Province. Witnesses say many scared local residents have run outdoors and some stay in cars, despite a freezing temperature of minus 20 degrees Celsius.

"I was waken up from sleep by the jolt," said a man surnamed Han in Xining, "The table and the closets were all shaking violently, so I just got dressed and run outside."

Photo/China Earthquake Networks Center