A fresh series of quakes hit the Aegean island of Santorini early on Thursday, part of an unprecedented seismic wave that has baffled scientists and led to a mass exodus of residents.

The hundreds of earthquakes that have rattled Greek islands on the Aegean Sea are a “seismic swarm" and could continue for weeks before eventually diminishing, the Santorini mayor told The Associated Press on Tuesday — pausing to chuckle as new tremors shook items on his desk.