An earthquake struck many parts of Britain early today, knocking out electricity and phone lines in some areas, but there were no reports of serious damage.
"It measured 4.8 on the Richter scale and the epicentre was around Dudley in the West Midlands [central England]," Mr David Galloway of the British Geological Survey said.
"It was relatively strong and we would expect this to happen only every 10 or 12 years," he said.
Buildings are only at risk when earthquakes reach a magnitude of 5 to 5.5 on the Richter scale, the British government's Environment Agency website said.
Tremors were felt by people as far afield as Wales in the west and London in the southeast shortly before one a.m.
"We have had hundreds of calls from people saying their houses were shaken and that buildings were wobbling," a spokesman for West Midlands police said. "Some electricity and phone lines went down," he said.
In London some residents called out the fire brigade.