Scientists have detected several thousand earthquakes, the vast majority of them with small magnitudes, in just over two weeks near Greece's volcanic island of Santorini, the University of Athens' crisis management committee said Tuesday,

The threat of a more major earthquake seems to have subsided on the most visited of the Greek islands but experts disagree on the origin of the tremors that have caused 11,000 of the 15,000 permanent residents to flee.

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

It welcomes around 3 million visitors per year, but between January 26 and February 8, the Seismology Laboratory of the University of Athens has registered a staggering 12,800 earthquakes in the Santorini-Amorgos zone, the strongest of these was last night at a magnitude of 5.3.

The Greek island of Santorini was struck by the latest in a string of earthquakes Tuesday, this time a 4.8 temblor. The government said it will backstop the island destination's tourist industry.

February marks the unofficial start of the tourist season in the Greek island of Santorini - when the first cruise ships are due to arrive and the Easter holidays approach. But with thousands of earthquakes shaking the island since January and experts unable to say when they will end,

Authorities declared a state of emergency on a second Greek island Wednesday as a series of earthquakes continued to rattle the south-eastern Aegean Sea region. The emergency measure announced on the island of Amorgos follows a similar decision for nearby Santorini on Feb.

Seismologists have noted that the epicentre of the earthquakes is steadily drifting northward in the direction of Amorgos.