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. Residents have been warned to avoid indoor gatherings,

Greek officials are warning those on the popular tourist island destination of Santorini to stay alert in the coming days due to increasing seismic activity which could mean a strong earthquake is possible.

A tourist sits at Firostefani as Greek authorities are taking emergency measures in response to intense seismic activity on the popular Aegean Sea holiday island of Santorini, southern Greece, Monday,