A magnitude 5.1 earthquake has struck southern Greece, the state-run ANA news agency has said.
The quake rattled the Greek capital, Athens, on Wednesday, causing buildings to shake for several seconds, the Reuters news agency quoted witnesses as saying.
There were no immediate reports of casualties or damage, police and fire brigade officials said.
The magnitude 5.1 quake struck northeast of Patras at a depth of 9.7 miles, the US Geological Survey said.
Thanassis Ganas, a seismologist with the Athens Observatory, said that the earthquake was "a normal tremor for the area".
"While the earthquake wasn't that strong it was felt because it was near the surface," an official at the Athens Geodynamic Institute said.
Greece is often rattled by earthquakes. While most cause no serious damage, a 5.9 magnitude quake killed 143 people in 1999.