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.

Tremors between Santorini and Amorgos since Friday led to school closures in Santorini, Ios, Amorgos, and Anafi, as authorities monitor the seismic activity.