Repeated earthquakes are rattling Greece’s volcanic island of Santorini. The quakes are prompting authorities to dispatch rescuers with tents, a sniffer dog and drones and to shut down schools on four islands.

Santorini, a popular tourist destination in Greece, was put on a on high alert following a series of over 200 undersea earthquakes between Santorini and another Greek island Amoros, in the past four days.