The quake struck about 400 miles east of the Tibetan capital of Lhasa, near China’s border with far northern Myanmar (Burma).
Residents rushed out of their homes before dawn, when the shaking started at 5:23 a.m. local time.
The U.S. Geological Survey said the epicenter was at the relatively shallow depth of 12 miles.
Aftershocks jolted the area for the following two days.
Three weeks earlier, a 6.6-magnitude quake jolted China’s Minxian and Zhangxian counties in the northwestern province of Gansu, killing at least 95 people.