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.

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.

Greek Prime Minister Kyriakos Mitsotakis has urged people on the island of Santorini to "stay calm" after an increase in seismic activity. His remarks come as schools were told to close on Monday and authorities advised against large gatherings in enclosed spaces across the island,