An earthquake measuring 5.1 on the Richter scale jolted parts of eastern France, southwestern Germany and western Switzerland, seismologists said.

The tremor plunged part of the French town of Besancon into darkness for more than one hour after it cut electricity supplies, but fire and police services reported no immediate casualties or major damage.
France's earth sciences observatory in Strasbourg said the epicenter of the quake, which struck at 6:31 pm (1731 GMT), was in Baume-les-Dames, a town of 6,000 people around 20 kilometres (12 miles) from Besancon.

France's electricity utility EDF said the power cut affected some 25,000 people in several areas of Besancon, including the town centre.

"I haven't heard of any consequences from the quake," Antoine Berthaut, head of Baume-les-Dames' town hall services department, told AFP.

The tremor was felt in an area stretching from the French cities of Lyon and Strasbourg to Geneva in Switzerland to southwestern Germany, and sparked worried calls to media stations and local services from inhabitants.