A 5.3-magnitude undersea earthquake struck off Greece\'s southern Peloponnese peninsula on Monday, news reports said, with no immediate confirmation of damage or injuries. The quake registered at 14:23 pm (1123 GMT) about 236 kilometers (147 miles) southwest of Athens, some 15 kilometers off the coast of Methoni in the Peloponnese, the reports said. Greece experiences more seismic activity than any other country in Europe, accounting for half of the continent\'s recorded quakes, and the Peloponnese has often been at the center of seismic activity. In 2008 a 6.5-magnitude earthquake struck the area, killing two people and injuring more than 30.