At least two people have been killed as an earthquake rocked southern Greece, collapsing buildings and causing panic.
Some 20 injuries were reported from falling roofs as the tremor - which had an epicentre 200km (124 miles) west of Athens - struck near Patras in the Peloponnese region.
The quake had a magnitude of 6.5, the Athens Geodynamic Institute said, and could be felt in the capital.
Greece is one of Europe's most earthquake-prone countries.
A 60-year-old man died when his home's roof collapsed on him, and an 80-year-old woman died of a heart attack after the quake shook her village, authorities said.
One terrifying minute
Experts have warned that aftershocks are likely as the quake's epicentre was close to the ground's surface.
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"The earthquake was terrifying," Patras resident Anna Tsokana told the BBC.
"The duration was about 60 seconds... Buildings have fallen or been damaged and roads have been destroyed."
The earthquake was one of the most powerful to hit Greece in modern times, says the BBC's Malcolm Brabant in Athens.
The US Geological Survey said the earthquake had a magnitude of 6.1.
A map showing the location of the Earthquake 
According to the United States Geological Survey (USGS), an earthquake with a magnitude of 6.1 has struck Greece. The epicenter was recorded 20 miles away from the city of Patras, and 125 miles away from Athens, the Greek capital. The earthquake occurred soon after 12:00 UTC today, according to the Athens Geodynamic Institute. The USGS originally reported the quake as a magnitude 6.5.

There have been reports of at least two people killed and 37 injured. There has also been damage to property and mobile phone networks which are being overloaded. There are also reports of families trapped inside the rubble of homes and businesses.

The control tower at Andravida airport is reported to have sustained serious damage and has been abandoned. Many buildings and homes are said to be severely damaged or collapsed.

The tremors from the earthquake were noticeable in large parts of Greece, including Athens, but the shaking could be felt as far away as Italy.

A nationwide mobilisation of civil defence and fire brigade units commenced after the natural disaster.  
 
Finally, schools were also ordered closed on Monday in the affected areas.