ATHENS — The Greek island of Santorini is being rattled by dozens of tremors, prompting authorities to close schools and airlines to announce additional flights on Monday to help people leave the popular tourist destination.

Over the past four days, more than 200 earthquakes have been recorded between Santorini and Amorgos in the Aegean Sea, with the strongest reaching a magnitude of 4.6.

Tremors, some with a magnitude above 4, continued to rattle Santorini on Monday. Although these quakes are considered minor or light, authorities have closed schools on Santorini, as well as on Amorgos, Ios and Anafi, and advised residents to avoid large indoor gatherings.

“The seismic activity continues regularly with the same intensity,” Vassilis Karasthathis, director at the Institute of Geodynamics at the National Observatory of Athens, told Greek media on Monday.

Aegean Airlines, Greece’s largest airline, announced two additional flights on Monday and one on Tuesday, traveling to and from Santorini, to help residents and visitors leave the island.

Nikos Zorzos, the mayor of the island, denied that there was a “mass exodus” from the island, and told Greek media that the majority of those leaving were seasonal workers, not permanent residents.

Sitting on several fault lines – known as the Hellenic Volcanic Arc – Santorini is no stranger to earthquakes. But the risk of tremors does not deter as many as 3.4 million people from visiting Santorini each year, dwarfing the 20,000 or so permanent residents of the island.

Santorini is famed for its crescent-shaped caldera, which was created by one of the largest known volcanic eruptions around 3,600 years ago. The tourist destination has been dubbed Greece’s “Instagram island” because of its photogenic golden light and sweeping scenery.

The Hellenic Volcanic Arc, one of the most active volcanic fields in Europe, has seen more than 100 eruptions over the past 400,000 years.

The most recent large quake in Santorini struck in 1956. The 7.5-magnitude earthquake was followed by a 25-meter-high (around 80 feet) tsunami. At least 53 people were killed and more than 100 injured, while at least one-third of the houses on the island collapsed.

Authorities said current seismic activity is due to tectonic movements that do not appear related to volcanic activity. Similarly, increased seismic activity in 2011 and 2012 did not result in any eruptions, they added.

In a sign of “good news,” Karasthathis said on Monday that the sequence of tremors appeared to be moving away from Santorini.

“As the distance increases, the chances of significant damage from anything decreases,” he said. — CNN