The governor said there was no immediate information on casualties.
Turkish media said the earthquake was felt across the regions of Aegean and Marmara, where Istanbul is located. Istanbul's governor said there were no reports of damage.
The quake was felt across the eastern Greek islands and even in the Greek capita,l Athens. Greek media said the residents of Samos and other islands fled their homes, while some rockfalls were reported. There were no immediate reports of injuries.
Both countries reported aftershocks.
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