Earthquakes rattled Greece’s volcanic island of Santorini every few minutes overnight and into Wednesday as authorities bolstered emergency plans in case the hundreds of temblors over the past few days are a harbinger of a larger quake to come.

ATHENS, Greece — Multiple earthquakes are rattling Santorini, a volcanic island in Greece, prompting authorities to dispatch rescuers with tents, a sniffer dog and drones, and to shut schools on four islands.

A 5.3 magnitude earthquake struck near Santorini, Greece, the latest in a series of temblors near the popular tourist destination.