No apparent injuries or damage, with epicentre located under the sea between island of Evia and the Greek mainland.
A magnitude 5.2 earthquake rattled Greece’s capital early on Tuesday but there were no immediate reports of damage or injuries.
The Geodynamic Institute in Athens said the quake occurred at 4.09am in the Gulf of Northern Evia, about 50 miles (80km) north of Athens in a narrow strip of sea between the island of Evia and mainland Greece.
Greece’s Civil Protection Agency said police in the city of Halkida, near the quake’s epicentre, and elsewhere in the surrounding region reported no damage.
Earth tremors and quakes are frequent in Greece and neighbouring Turkey.
“It was an earthquake that occurred quite near the surface and was felt quite intensely in Athens — from an area where quakes are fairly common but rarely stronger than today’s event,” said seismologist Efthimios Lekkas, director of the state-run Earthquake Planning and Protection Organisation.
“There have already been two aftershocks after this earthquake ... I don’t think there is any particular cause for concern.”
The US Geological Survey recorded the earthquake as being of magnitude 5.2 and a depth of 3.6 miles.