Experts say the Greek island of Santorini has been hit by more than 1,000 earthquakes, but they're not linked to the region's active volcanoes.

Greece has declared a state of emergency on Santorini after hundreds of undersea earthquakes shook the resort island for nearly a week.

According to officials, more than 11,000 people have left Santorini, with around 7,000 departing by ferry and 4,000 people leaving by air. Hundreds of earthquakes have rocked the island, the strongest of which was a magnitude five tremor on Tuesday.