JOIN USLocal police said they had no immediate reports of damage or injuries.
The quake had a preliminary magnitude of 6.2 and struck off the southern coast of Crete at 4:29 pm (1859 hrs IST), the Athens Geological Institute and the German Research Centre for Geosciences in Potsdam, Germany, said.
The US Geological Survey gave a slightly lower preliminary magnitude of 5.9. Magnitudes recorded by geological institutes often differ.
Police in Ierapetra, a town on the southern coast of Crete closest to the epicenter, said it was strongly felt but that they had no initial reports of damage or injuries.
The quake was felt as far away as Cairo across the Mediterranean Sea, and the Turkish news agency Anatolia said it also caused panic in the Turkish resorts of Bodrum, Fethiye and Marmaris.
"It was a strong earthquake in a region that is in the eastern section of area known as the Aegean Arc," said Manolis Skordilis, Associate Professor of Seismology at the University of Thessaloniki in northern Greece.
"This is a very seismically active area that has seen more powerful quakes in the past. We are monitoring the post-earthquake activity, which so far is not intense," he said.
Greece is one of the most earthquake-prone countries in the world, but the thousands of quakes recorded each year rarely cause severe damage or fatalities.
In June 2008, a 6.5-magnitude quake struck near the western port city of Patras, about 120 miles west of Athens, killing two people, injuring more than 200 and damaging hundreds of buildings. In 1999, a magnitude 5.9 quake near Athens killed 143 people.