Residents have been warned to avoid indoor gatherings, check escape routes, stay away from cliffs and to drain swimming pools ...

More Greek islands closed schools Tuesday as hundreds of earthquakes ratted the Aegean Sea, while a handful of hardy tourists enjoyed having Santorini’s stunning views to themselves.

Although Greece is no stranger to earthquakes, seismic activity of such frequency and intensity without having been preceded by a major quake is unusual, seismologists say.