A magnitude-4.2 undersea quake rattled parts of the southern Peloponnese region early Tuesday, authorities said.

There were no reports of damage or injuries.

The Athens Geodynamic Institute said the quake struck at 7:13 a.m. some 14 kilometers east of the village of Kotronas in eastern Mani, at a depth of 8.8 kilometers.

Greece is in one of the world’s most earthquake-prone areas, and the Peloponnese is one of the country’s most seismically active regions.