SANTORINI, Greece >> 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.

“This phenomenon may play out with small quakes or a single, slightly stronger one, followed by gradual subsidence,” said Mayor Nikos Zorzos, adding he was cautiously optimistic after speaking to seismologists who described the swarm as a series of tremors of similar magnitude occurring in clusters.

Thousands of residents and seasonal workers have left the Cycladic Islands as quakes up to magnitude 5 have been recorded in the volcanic region since Friday. Ferry and commercial flight operators have added services to accommodate departures. More Greek islands closed schools Tuesday.

A handful of hardy tourists enjoyed having Santorini’s stunning views to themselves.

Santorini earlier canceled public events, restricted travel to the island and banned construction work in certain areas. The quakes have caused cracks in some older buildings, but no injuries have been reported.

In Santorini’s main town, Fira, the narrow, whitewashed streets along the island’s clifftops were deserted — a rare sight even in the off-season — except for small pockets of tour groups

Joseph Liu, of Guangzhou in southern China, said he had wanted to visit Santorini for years after seeing it in a documentary.

“This place is amazing, really beautiful,” he said, adding that the tour group leader had told him and others about the quakes before they arrived, “so it was not a surprise.”