
The quake was 32 kilometres (20 miles) deep, USGS said, with its epicentre in a sparsely-populated area of Yushu prefecture. There was a "low likelihood of casualties and damage", it said.
Yushu was the scene of a 6.9-magnitude earthquake in April 2010 that left nearly 2,700 people dead and more than 12,000 injured, according to state news reports.
In 2011 it was struck by a 5.3-magnitude quake.
The region, situated on the remote Qinghai-Tibetan plateau, is largely inhabited by ethnic Tibetans.
The China Earthquake Network Centre gave the latest tremor a magnitude of 6.2 and a depth of nine kilometres, with its epicentre in Zadoi county.