WASHINGTON (REUTERS) - A strong magnitude 6.1 earthquake struck off western Greece early on Monday, the United States Geological Survey (USGS) said.

The quake, which was initially reported as 6.4 in magnitude, struck 122km west of Patras at a relatively shallow depth of 13.7km at 0308 GMT (11.08am Singapore time), the USGS said.

There were no immediate reports of injuries or damage.

A 5.8-magnitude earthquake struck the same region late last month. That quake was felt on several Ionian islands and as far away as the capital Athens.

Greece is one of Europe's most earthquake-prone countries. Cephalonia has previously been struck on several occasions and in August 1953 virtually every house on the island was destroyed during a major earthquake.

The island was also the setting for the popular novel Captain Corelli's Mandolin, about a Second World War romance between an Italian soldier and a local woman. A 2001 movie of the same name, starring Nicolas Cage and Penelope Cruz, was filmed on the island.

The Mediterranean region as a whole is seismically active due to the convergence of the African and Eurasian tectonic plates.