Representative image. Photograph:( Reuters )
Local media reported damage caused by landslides and electricity outages.
A strong quake with a magnitude of at least 6.4 struck off Greece early on Friday, earthquake monitors said. There were no initial reports of extensive damage or casualties.
The epicentre of the quake, initially reported as a magnitude 7.0, was in the Ionian Sea, some 83 miles (133.5 km) southwest of Patras in the Peloponnese.
A fire brigade official in Athens said there were no early reports of damage or casualties. Attention was focused on the island of Zakynthos, where reports indicated power was out.
Local news websites reported that a 15th century monastery in the Strofades area of the island had been damaged.
The tremor was felt in Greece`s capital, Athens, and as far away as Italy.
Italy’s Il Messaggero online news site reported that the quake had been felt hundreds of kilometres away in southern Italy. Firefighters in Sicily, Calabria and Puglia received thousands of telephone calls for information about the quake.
The quake was fairly shallow, only 10.3 miles (16.5 km) below the seabed, which would have amplified shaking.
It struck at 1:54 a.m. (2254 GMT Thursday) and was followed about half an hour later by a 5.2 aftershock.Greece straddles two tectonic plates and often gets earthquakes.
Greece`s Geodynamic Institute reported a tremor of 6.4, 50 kilometres south of Zakynthos. An official there confirmed a tsunami alert had been issued, which is standard for tremors over 5.5.
The US Geological Survey (USGS) put the quake at 6.8.
"It was strong, things fell of the shelves," a witness in Katastari, Greece, 36 kilometres north of the epicentre, wrote on the European-Mediterranean Seismological Centre (EMSC) website.
Soon after the quake there were only 3 postings on the EMSC testimonials page, which is unusual for a quake of such magnitude.