Big tremor deep below China

A powerful earthquake measuring more than seven on the Richter scale has shaken an area of north-eastern China bordering North Korea and Russia.

There are no reports of deaths or major damage.

Seismologists say the centre of the quake was some 500 kilometres beneath the surface of the Earth, greatly reducing its impact.

Although the tremor could be felt hundreds of kilometres away - in places such as the Russian city of Vladivostok - some residents in areas relatively close to the epicentre in Jilin province were not aware of it.

A BBC correspondent says such strong seismic activity will cause concern in a country which suffered the worst earthquake of the 20th Century in Tangshan in 1976, when more than 200,000 people were killed.

From the newsroom of the BBC World Service