A new earthquake swarm rattled Santorini early Thursday, adding to an unprecedented seismic wave that has puzzled scientists and driven a mass exodus

Earthquakes rattled Greece’s volcanic island of Santorini every few minutes through the night and into Wednesday as authorities bolstered their emergency plans in case the hundreds of temblors over the past few days are a harbinger of a larger quake to come.

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.