A 5.5-magnitude earthquake struck off the coast of southern Greece near Methoni, according to the US Geological Survey (USGS), while a second earthquake hit the north of the country, near the city of Thessaloniki.

The tremors of the first quake hit in the early hours of the morning in the south of the country, where nearby towns are known for historic architecture.

“The earthquake had a long duration and initially we were worried," Dimitris Kafantaris, the Mayor of Pylos, a small town in the country's south west, told the Greek Reporter news portal.

The chief executive of the South West London and St George's Mental Health NHS Trust tweeted about being woken up by the earthquake.

"Well that’s a first for me. Woken on holiday by the room shaking as we felt #earthquake off coast of Greece," he wrote.

The latest estimates from the Geodynamic Institute of Athens, suggest the epicentre of the quake was in the Ionian Sea, with a depth of around four-and-a-half miles.

Well that’s a first for me. Woken on holiday by the room shaking as we felt #earthquake off coast of Greece pic.twitter.com/yT1i85h9kS

However, the USGS suggested the earthquake was in fact 18.6 miles deep and its epicentre was recorded as being 16 miles from Methoni.

However, Gerasimos Papadopoulos, the head of the Athens Geodynamic Institute, told Greek television station TV ERT, that an aftershock with a 3.3-magnitude was also recorded.

The tremors occurred in the Peloponnese, which is a peninsula to the south of mainland Greece, linked by the Corinth canal.

Another earthquake hit the northeast of the country later this morning, measured as a 4.2 magnitude by the Athens Geodynamic Insitute. It was recorded about 20 miles away from the port city of Thessaloniki at around 3.1miles deep.

In June 2008, two people died and around 240 were injured when a 6.4-magnitude quake struck the region.