Local resident Margaret Williams

The earthquake registered three on the Richter scale and its effects were felt in Merthyr Tydfil and Pontypridd.

Seismologists have said it is rare that a quake is felt by residents in the UK but they have insisted the event is nothing to worry about.

South Wales Police said they received a number of calls from worried members of the public.

They said people were concerned but there were no reports of any injuries relating to the incident.

Margaret Williams from Bargoed said: "I felt something shake the room. It only lasted for a second or two."

Glenn Ford, from the British Geological Survey, admitted that the quake was unusual, but was quick to reassure anyone who was worried.

We only get around three earthquakes of this size in the UK every year

Seismologist Glenn Ford

He said: "It was unusual because it was felt by the general public.

"We only get around three earthquakes of this size in the UK every year."

Mr Ford said that it was just one of about 200 tremors to hit the UK every year, and that only 10% of these were noticed by the public.

Describing earthquakes in the UK as a "nuisance" he said: "When you compare them to the quakes outside Britain, these seismic activities are tiny.

"There is unlikely to be any devastation.

"The Bargoed tremor was 24m times smaller than the earthquake in India."

Tremor warning

But Mr Ford did warn of a larger tremor which could hit at any time.

He said: "We are expecting a magnitude five earthquake which usually occurs every ten years.

"We can't say when and we can't say where, but it will only topple a few chimney pots or displace a few slates."

Since 1580, 11 people have died as a result of earthquakes in the UK since 1580.

The biggest recorded onshore earthquake in the UK occurred in Lleyn, north Wales on 19 July 1984.

Measuring 5.4 on the Richter scale, its effects were felt over an area of about 240,000 sq km.