BEIJING (AFP) - An earthquake with a magnitude of 7.3 jolted China's north-western Qinghai province early on Saturday (May 22), the US Geological Survey said - following another tremor in the country's south-west that left at least two dead.

The epicentre of the quake in Qinghai, which struck at 2.04am at a relatively shallow depth of 10 kilometres, was located about 400km south-west of the city of Xining, US seismologists said.

The quake was initially measured at a magnitude of 7.4 but then slightly revised downwards by the USGS.

The sparsely populated province is spread across the Tibetan plateau.

In 2010, a 6.9-magnitude quake in Qinghai left 3,000 people dead or missing.