There were no reports of injuries, although some older buildings suffered damage.
The German Research Center for Geosciences (GFZ) earlier reported the tremor as having a magnitude of 5.8.
The Greek Geodynamic Institute said the quake struck at 11:43 p.m. two km (1.2 miles) from the town of Florina and at a depth of 14 km.
Authorities said schools will remain closed on Monday for precautionary and safety reasons.
Costas Papazachos, the President of the Department of Geology of the Aristotle University of Thessaloniki, said that he expects a significant post-earthquake sequence.
Speaking to AMNA, he noted that the epicenter of the earthquake was very close to Florina and the tremor was particularly felt in the city.
“The area is of low seismicity and has many faults that are completely unknown, like the one that gave Sunday’s earthquake which is not mapped by the scientific community,” he stressed.
Greece is especially earthquake-prone
Greece lies in a highly seismically active region. The vast majority of earthquakes cause no damage or injuries, however.
The country is located in a complex geological boundary zone in the eastern Mediterranean between the African Plate and the Eurasian Plate.
The northern part of Greece lies on the Eurasian Plate while the southern part lies on the Aegean Sea Plate.
The Aegean Sea Plate is moving southwestward with respect to the Eurasian Plate at about 30 mm (1 inch) per year while the African Plate is subducting northward, beneath the Aegean Sea Plate, at a rate of about 40 mm (1.6 inches) per year.
The northern plate boundary is a relatively diffuse divergent boundary while the southern convergent boundary forms the Hellenic Arc.