The magnitude 5.3 temblor struck Tibet's Naqu region, a wide swath of grasslands a few hundred kilometers north of the regional capital Lhasa, a duty officer with the Chinese seismological bureau said.

There were no immediate reports of damage or injuries.

A railway official at the Xining station along China's Beijing-Tibet train told The Associated Press that service on the line appeared to be unaffected by the quake. The Sky Rail service, which climbs to the highest elevation of any train in the world and is laid over delicate permafrost, cuts through Naqu.

The Hong Kong Observatory also detected the quake, reporting it as a magnitude-5.0 temblor that occurred at 9:55am, with an epicenter 400 kilometers north of Lhasa.