UPDATE 3: Right after the earthquake there 20.000 phone calls per second(!) were made through the mobile phone networks.
UPDATE 2: The latest aftershock is the most powerful so far, being 4.4 on the Richter scale.
UPDATE: Powerful aftershocks shake Athens.
There are reports of minor injuries from shuttered glasses but nothing alarming thus far.
A powerful 5.1 earthquake struck Athens on Friday at approximately 2.13 in the afternoon.
According to the Euro Mediterranean Institute, the epicenter is located 34 kilometers northwest of Athens and at a depth of 5 kilometers, close to the foot of Parnitha mountain.
The earthquake, which was felt throughout the whole country, is estimated to have lasted 15 seconds. After the tremor, and possibly due to network overload, problems have been reported in communication and the electricity grid.
Two aftershocks followed the initial tremor. Many people panicked and run out to the streets.