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

The latest of hundreds of earthquakes rattled the volcanic Greek island of Santorini on Tuesday after the strongest one so far with magnitude 5.3. Medical staff staged a hospital evacuation drill as scientists say it's unclear whether the weeks of highly unusual seismic activity precede a larger quake.

A state of emergency has been declred in Santorini, a volcanic island and popular tourist destination in Greece, as an 'earthquake swarm' that began earlier this month continues. Since 31 January, more than 800 tremors with a magnitude of three and above have been recorded.