TEMPO.CO, Athens - A strong quake of magnitude 6.8 struck off Greece early on Friday, the U.S. Geological Survey said, but there were no initial reports of damage or casualties.
The epicenter of thequake,initially reported as a magnitude 7.0, was in the Ionian Sea, some 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.
The quake was fairly shallow, only 16.5 km below the seabed, which would have amplified the shaking.
It struck at 1:54 a.m. local time and was followed about half an hour later by a 5.2 aftershock.
Greece straddles two tectonic plates and often gets earthquakes.