A moderate quake measuring 5.2 on the Richter scale, according to immediate calculations, was recorded at just after midnight (00.27 local time, 22.27 GMT), with an epicenter near the southern Evia Island harbor town of Karystos.

The earthquake was particularly felt in the greater Athens-Piraeus area (more than 45 kilometers) to the southwest, with the tremor lasting for several agonizing seconds.

The automatic reading by the Athens Observatory’s Geodynamic Institute has the quake at 5.3 on the Richter scale, with other reports citing varying degrees of magnitude. The exact epicenter was pinpointed at four kilometers north, northwest of the coastal resort of Nea Styra, which is located on the eastern shores of the southern Evoikos Gulf. The focal depth was given at 2.3 kilometers.

The location means the quake was centered in the sea region separating Nea Styra with the Schinias shoreline on the opposite Attica prefecture coast, near the iconic Marathon battlefield.