SHANGHAI - A moderate earthquake centred in the Yellow Sea off China's eastern coast rattled Shanghai on Wednesday, causing buildings to shake but no immediate damage or casualties.

The earthquake, which had a magnitude of 5.0, took place at 9:19 am (0119 GMT), and the epicentre was located 270 kilometres (170 miles) northeast of Shanghai, the US Geological Survey said.

The quake occurred at a depth of 18.5 kilometres, it said.

There were no immediate reports of casualties or damage, but many people in downtown Shanghai reported feeling the tremor, which lasted a few seconds, on Twitter and other microblogging sites.