At least four people have been injured on the Greek island of Samos following the quake.
Nikos Stefanis, the president of Samos Hospital, said all four injuries had been minor and suffered by individuals with orthopaedic problems.
He said there was building damage across the island, with the worst sustained in the area of Karlovasi, in northwest Samos.
Describing the quake, Stefanis said it as very strong and had lasted a long time.
Samos Deputy Mayor Giorgos Dionisiou told Greek media that the collapsed buildings were mainly old ones.
The Greek Fire Service in a statement said that so far, only damage to buildings had been reported. The statement said there had been no calls about trapped people.
Even so, the people of Samos have been told by Greek authorities to stay away from the island's shores and buildings.
Residents have also been asked to evacuate their houses for the next 48 hours for precautionary reasons.
Greece's Geodynamic Institute said the epicenter was in the sea 19 kilometers north of the island of Samos.