New Delhi, Feb. 3 -- As dozens of tremors shook the Greek island of Santorini for a fourth day, schools remained shut and additional flights were scheduled to help people leave the region on Monday. Schools were also closed in nearby islands of Ios, Amorgos and Anafi.

Tremors have been recorded between the volcanic islands of Santorini and Amorgos in the Aegean Sea since Friday.

Quakes, some with a magnitude of over 4, rattled Santorini every few minutes on Monday as people were advised to stay outdoor.

Disaster response units were deployed on the ground.

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 ove...