ATHENS (Reuters) - An earthquake of 5.0 magnitude struck in the Mediterranean just off Greece's southern coast on Sunday, the U.S. Geological Survey said, but there were no immediate reports of injuries or damage.

The quake occurred at 7:42 a.m. (0542 GMT), 34 miles southwest of the coastal city of Kalamata in the Peloponnese region, the Survey said.

Greece is often rattled by earthquakes. While most cause no serious damage, a 5.9 magnitude quake killed 143 people in 1999.

(Reporting by Karolina Tagaris; Editing by Andrew Heavens)