THESSALONIKI, Greece (AP) — A strong earthquake has shaken the Greek tourist island of Zakynthos in the Ionian Sea.

The U.S. Geological Survey says the 6.8 magnitude quake was 35.9 kilometers (22.3 miles) southwest of Lithakia in the southern part of Zakynthos. It had a depth of 16 kilometers and struck at 22:55 GMT on Thursday.

Greece lies in one of the world's most earthquake-prone regions, with thousands of quakes recorded every year. But few cause injuries or significant damage.

Zakynthos has had severe earthquakes in the past, and as a result has a very strict building safety code.