Greek authorities have warned of an increase in seismic activity around the Aegean tourist island of Santorini, advising people to avoid four ports, empty their pools, refrain from gathering in indoor spaces and shut schools on Monday.

The strongest earthquake recorded was magnitude 4.6 at 3:55 p.m. Sunday, at a depth of 14 kilometers (9 miles), the Athens Geodynamic Institute said.

Earthquakes measuring between 2.8 and 4.5 struck the area on Sunday morning, according to the Athens Geodynamic institute, without causing damage. Greece sits on multiple fault lines and is often rattled by earthquakes. Santorini is one of Greece's top tourist destinations.

Greece's tourist island of Santorini on Sunday braced for the prospect of more tremors after more than 200 small earthquakes shook the site of one of the largest volcanic eruptions in recorded history,

The Foreign Office has issued a warning for British travellers hoping to visit one of Greece’s most popular islands. Schools on Santorini have been forced to close down following an increase in seismic activity in the area.