The U.S. Geological Survey said the quake struck at 2:17 p.m. on Wednesday, 69 miles south of the island's city of Iraklion and 262 miles southeast of the Greek capital, Athens.

The European-Mediterranean Seismological Center gave the preliminary magnitude as 5.5. Magnitudes given by different seismological centers often vary.

Greece is one of the world's most earthquake-prone countries, but most quakes are of small magnitude and rarely cause severe damage or injuries.