An earthquake measuring a magnitude of 6.9 hit Nyingchi, southwest China's Tibet Autonomous Region, in the early hours of Saturday, according to the China Earthquake Networks Center (CENC).No casualty has been reported after the quake which struck at 6:34 a.m. on Saturday (Beijing Time), Xinhua news agency reported.However, the quake caused power failure and building damages in a number of villages in the epicenter in Nyingchi City.The epicenter was monitored at 29.75 degrees north latitude and 95.02 degrees east longitude.The quake struck at a depth of about 10 km.