SANTORINI, Greece — Authorities deployed emergency rescue crews to Greece’s volcanic island of Santorini on Monday as hundreds of people scrambled to leave after a spike in seismic activity raised concerns about a potentially powerful earthquake. Schools on four islands were also to shutter through Friday. Precautions were also ordered on several nearby Aegean Sea islands — all popular summer vacation destinations — after more than 200 undersea earthquakes were recorded in the area over the past three days.

Mobile phones on the island blared with alert warnings about the potential for rockslides, while several earthquakes caused loud rumbles. Authorities banned access to some seaside areas, including the island’s old port, that are in close proximity to cliffs.

“These measures are precautionary, and authorities will remain vigilant,” Civil Protection Minister Vasilis Kikilias said late Sunday following an emergency government meeting in Athens. “We urge citizens to strictly adhere to safety recommendations to minimize risk.”

– The Associated Press