
Police had not received reports of injuries, Greek state radio NERIT reported.
The ground shook noticeably across the region, including all of Crete and the islands of Kasos, Karpathos and Rhodos, according to media reports.
"It lasted about 30 seconds. We are all OK, but we were all frightened," Christos Pilatakis, the operator of a hotel on Rhodes, told dpa.
The duty officer at the police station in the southern Crete resort town of Ierapetra told dpa there appeared to be no damages.
"Nothing has been reported to us," he said two hours after the quake.
Geological authorities in Athens said they had recorded aftershocks of 3.9 to 4.9 magnitude. Sea earthquakes are a frequent occurrence in the region. The European and African continental shelves push up against each other south of Crete.