According to the US Geological Survey the quake had a 6.4 magnitude, while the Athens Observatory gave it a magnitude of 6.2.
The epicentre was some 60 kilometres off the city of Hania in western Crete, the state-run Athens News Agency said.
The earthquake struck at 4:11 pm (1841 IST) and its epicentre was in the sea, 275 kilometres south of Athens, the Athens Observatory announced, describing the quake as "strong".
"It was very impressive because the shaking lasted some 40-50 seconds," a woman who identified herself only as Vassia, told an AFP reporter on the island.
According to Skai radio station, houses and shops in Hania were damaged while one person was lightly injured while attempting to jump out a window.
Local media further reported that fallen rocks had blocked a road close to Hania.
Greece is one of Europe's most earthquake-prone countries.
