Residents ran out into the streets after a strong earthquake hit the Greek capital Athens.
The shock was caught live in the studios of state broadcaster ERT.
The Athens Institute of Geodynamics gave the earthquake a preliminary magnitude of 5.1.
There was no immediate word on injuries or damage on Friday afternoon.
The quake sparked limited power cuts around Athens and the fire brigade reported receiving calls about people trapped in building elevators.
The Civil Protection Authority said that police and volunteers north of the capital were carrying out searches for possible damage.
The most powerful quake to hit the Greek capital in the last 20 years came in 1999, when a quake of magnitude 6.0 caused extensive damage and killed more than 140 people.
Gerasimos Papadopoulos, the senior seismologist at the Geodynamics institute, said Friday's quake was felt across southern Greece.
"It had a very shallow depth and that's why it was felt so strongly," he said.
"It is too early to say whether this was the main earthquake, but there have been aftershocks of magnitude 3.5, 2.5 and 3.2 and that is encouraging. But we need more time and data to have a clear picture."
Earthquakes are common in Greece and neighbouring Turkey.
