Greek authorities say an earthquake with preliminary 5.3-magnitude has shaken the southern Aegean Sea islands, but no injuries or damage have been reported. The Athens Geodynamic Institute says the undersea earthquake occurred Thursday between the popular tourist resort islands of Santorini and Crete, some 244 kilometers (150 miles) southeast of Athens. Greece is in one of the world's seismically active areas. Out of the hundreds of quakes that occur every year, very few cause injuries or damage, although a strong earthquake on the outskirts of Athens in 1999 killed 143 people, AP reported.