SANTORINI, Greece — Earthquakes rattled Greece’s volcanic island of Santorini every few minutes overnight and into Wednesday as authorities bolstered emergency plans in case the hundreds of temblors over the past few days are a harbinger of a larger quake to come.

A coast guard vessel and a military landing craft were in the wider area in case an evacuation is required, Civil Protection Minister Vassilis Kikilias told an emergency meeting with security officials, scientists and the prime minister in Athens.

“We are obliged to draw up scenarios for better and for worse,” Kikilias said during the meeting, which was televised live.

Greece lies in a highly seismically active area and earthquakes are frequent. But it is extremely rare for any part of the country to experience such an intense barrage of frequent earthquakes.

Predicting earthquakes is not scientifically possible, and experts cannot determine definitively whether the seismic activity between the islands of Santorini and Amorgos is a precursor to a significantly larger earthquake, or is part of weeks or months of small or moderate intensity quakes.

“I understand the fear of what it means at the moment to be on a Santorini that is constantly moving,” Prime Minister Kyriakos Mitsotakis said, as he called on residents to remain calm.

Authorities have banned access to several coastal areas and ordered schools on several islands to shut for the week. Public events on Santorini have been banned, and authorities were restricting access to clifftop areas that are among the island’s biggest tourist draws.

Thousands of residents and visitors have left Santorini, frightened by the earthquakes measuring between magnitude 3 and magnitude 5 in the area since the weekend. Ferry lines and commercial airlines have added flights and ships to their schedules to accommodate the increased demand, although rough weather disrupted ferry services Wednesday.

The quakes have not caused injuries or major damage.

The Ministry of Digital Governance said a mobile unit for satellite communications was being transported to Santorini, while telecoms providers sent generators and mobile telecoms units to Santorini and the nearby islands of Anafi, Amorgos and Ios.

It also announced a digital platform — mysafetyplan.gov.gr — with maps showing areas designated as safe gathering points in the event of a natural disaster.

Authorities said monitors had picked up increased volcanic activity within Santorini’s caldera, or flooded crater, but scientists say this is unrelated to the quakes. They have said the seismic activity northeast of the island is unlikely to trigger either of the two volcanoes in the area.

Becatoros reported from Athens, Greece.