HONG KONG (AFP) - Thousands of people in Hong Kong contacted city authorities Friday saying they had felt the ground shaking following an earthquake across the border in southern China, an official said.

While earthquakes are not uncommon in China it is unusual for them to be felt in the southern financial hub.

The Hong Kong Observatory said the 4.8-magnitude quake struck in Guangdong province shortly before noon about 180 kilometres north of the city.

"People felt it indoors and they reported hanging objects swinging. It lasted for a few seconds," the Observatory's scientific officer Leung Yin-kong said.

He told AFP that some 5,000 people had contacted the agency to report feeling tremors, but there were no reports of damage. Some residents told local media the quake had caused buildings to sway and objects to fall from shelves.