An earthquake of magnitude 5.1 occurred at 1:02 a.m. local time Sunday near Delphi in the region of Phocis in central Greece.
The epicenter was twelve kilometers south of Desphina and sixteen kilometers southeast of Delphi and the harbor city of Itea.
The earthquake hit a shallow depth of 13.3 kilometers, the National Observatory of Athens (NOA) reported.
There have been no reports of damage although the tremor was felt in Attica and other regions of Greece, mainly in the areas around the Gulf of Corinth.
Aftershocks were observed during the night several times, and, in the morning, seismologists said they were still waiting to determine whether the 5.1 tremor was the main earthquake.
Speaking to Greek public broadcaster ERT, Geology Professor Efthymios Lekkas, President of the Greek Organisation for Antiseismic Planning and Protection, reassured residents.
He said the area is regularly impacted by seismic activity and is very resilient to earthquakes of this magnitude. The professor reminded the public that the area had even sustained a 6.7 magnitude earthquake in 1955.
The modern administrative unit of Phocis in central Greece is named after the ancient region which included Delphi in antiquity although the modern region is substantially larger than the ancient one.