A strong earthquake measuring 6.5 on the Richter scale rocked southern Greece Thursday and was felt as far away as Cairo, but there were no reports of injuries or damage, the Athens Geodynamic Institute said.

The underwater earthquake, which took place at 12:09 p.m. (1009 GMT), had an epicentre about 225 km southwest of Athens, in the area of Methoni, near the southern Peloponnese city of Kalamata.

Seismologists said the quake struck at a depth of 30 km, which probably minimised the damage, and lasted for about 15 seconds.

The earthquake was felt in the Greek capital Athens, throughout the Peloponnese, as well as the western port city of Patras and the southern Mediterranean island of Crete.

Reports said school children around the city of Kalamata were immediately evacuated from all schools in the area.

'It was very strong and lasted a long time,' said Theodoros Salantis, the mayor of Koroni, near the seaside town of Kalamata.

Local officials in the area said there were no immediate reports of damage to houses or injuries.

Seismologists said there would likely be aftershocks but they would be of a lesser magnitude. They advised people in the areas near the epicentre to stay away from buildings.

The Peloponnese was hit with another earthquake, measuring 5.4, ten days ago, near the city of Patras.