A destructive quake struck approximately 133.5 kilometres southwest of Patras, with tremors hitting the tourist hotspot of Zakynthos at 1.50am local time on Friday morning (11.50pm on Thursday). Details about damage or casualties were not immediately available.
The natural disaster struck at 1.54 am in the Ionian sea, around 30 miles off the coast of Zante and sent out tremors felt as far afield as Libya, Italy, Malta and Albania.
A Greek resident filmed the powerful earthquake's after-effects.
The quake rattled the whole of western Greece and was strongly felt in the capital, 174 miles to the north-east of Zakynthos. Power outages have been reported on the Greek island of Zakynthos, according to a local official. They also left large cracks in the port of Zakynthos, though authorities there said operations would continue as usual. 'Calm is being restored'. Shaking was felt across the region, as far away as southern Italy, Malta, Albania, and Macedonia. Firefighters in Calabria, Puglia and Sicily received thousands of telephone calls from anxious locals.
'The energy unleashed, based on the angle of the faultline, fanned out towards Italy, ' he added.
The most recent quake to claim lives, was in 1999 where the magnitude was recorded at 5.9 which killed 143 people on the outskirts of Athens.
On Twitter, the EMSC is cautioning that while in most places the wave will likely be limited to 20cm (about 7in) high, it could be significantly bigger locally.
However, over the years, few injuries have been reported, and structural damages due to earthquakes have been minimal.
Zante has had severe earthquakes in the past, and as a result has a very strict building safety code.