China's north-western region of Qinghai has been struck by a magnitude 6.6 earthquake, the authorities say.
A local official said the epicentre was located near the town of Delingha, northwest of the provincial capital Xining.
"Reports from Delingha and the surrounding area haven't said there are any casualties or damage yet," the official told Associated Press news agency.
He added that the tremor could be felt in Xining, some 500 kilometres (300 miles) from the epicentre.
Another local official said he had heard houses had collapsed.
In February the neighbouring Xinjiang region in China's far-west was hit by a quake of magnitude 6.8.
More than 260 people died and almost 10,000 homes were destroyed in that earthquake.