A moderately strong earthquake with preliminary magnitude 3.4 shook the island of Hydra before dawn Wednesday but no damage or injuries were reported.
The Athens Geodynamic Institute said the undersea quake occurred 5.5 kilometers northwest of Hydra, between the island and the northeastern Peloponnese, at a depth of 14.8 kilometers.
Earthquakes are very common in Greece, which is in one of the most seismically active parts of the world, but rarely cause severe damage or deaths.
In 1999, a magnitude 5.9 quake near Athens killed 143 people.
