Several smaller earthquakes have been registered in the sea around the Greek tourist island of Santorini and the authorities have now ordered schools to remain closed on Monday.
On Sunday, dozens of smaller quakes, with magnitudes between 4.1 and 4.5, were registered in the area. The strongest quake registered during the recent activity had a magnitude of 4.6.
According to the authorities, the quakes are not due to volcanic activity but are a result of movements in tectonic plates in the area.
Residents are advised to avoid large gatherings in enclosed spaces and to stay away from certain built-up areas.
Santorini is one of Greece's most popular tourist islands. The island has only 15,500 permanent residents but is visited annually by several million tourists.
