A strong earthquake shook western Greece on Friday morning, but no casualties were reported.

The Greek Geodynamic Institute in Athens, said the 5.8 magnitude quake occurred at 9:12 am (0812 GMT) local time.

The epicentre of the quake was about 20 kilometres below the seabed off the west coast of the Peloponnese peninsula near the islet of Stamfani, also known as Strofades.

It was preceded by a smaller quake with a magnitude of 4.1.

Greece’s Civil Defence organisation did not initially say whether there were any casualties or damage to buildings.

A tsunami warning was not issued.

“We felt the tremors very strongly,” a resident of the nearby Olympia region said, adding that “everyone here is on the streets.”

Local media reported that many schools had been evacuated as the quake was felt throughout western Greece, and on the tourist island of Zakynthos and as far away as Athens, about 300 kilometres away.

The deepest point of the Mediterranean Sea is located between western Greece and Sicily in Italy, with a depth of over 5,000 metres.

The African and European tectonic plates meet in this region, which makes it prone to strong earthquakes.