A shallow 5.4-magnitude earthquake struck eastern China, the US Geological Survey (USGS) said, with state media reporting at least 21 people injured and dozens of buildings collapsed.

The quake, which struck at 2:33 am (1833 GMT Saturday), hit 26 kilometres south of the city of Dezhou in Shandong province, at a depth of 10 kilometres.

It was the strongest to hit the province in more than a decade, state-run tabloid the Global Times said.