ROME, Jan. 18 (Xinhua) -- Central Italy trembled Wednesday, with a series of earthquakes causing widespread structural damage, halting transport systems, and chasing thousands of Italians from their homes, schools, and places of work.
Experts suggested Italian people should keep vigilant since more earthquakes are not impossible.
It was the third time in less than five months that the middle section was shaken by a series of temblors measuring at least 5.5 on the Richter scale.
Earthquakes in the range of 5.0 to 5.9 are strong enough to damage buildings and infrastructure, and are the weakest level events that can easily be felt by residents without special equipment, even a hundred kilometers or more from the epicenter.
Wednesday's events centered near Amatrice featured at least a dozen earthquakes and aftershocks measuring 5.0 or higher on the Richter scale, the most powerful, a quake measuring 5.7 on the scale.
That is significant, but still much weaker than the 6.5-magnitude temblor the shook the area near Perugia in October 2016, or the 6.2-magnitude quake near Amatrice in August 2016.
The Perugia quake caused major damage to buildings and resulted in three deaths and left more than 100,000 homeless. The 6.2-magnitude quake near Amatrice left nearly 300 dead in its wake.
The latest round was the least serious of the three recent sets of earthquakes.
It was felt as far away as Naples, around 275 kilometers from Amatrice, and it disrupted events in Rome, around 125 kilometers away, where schools and many office buildings were vacated, and service on the subway was suspended for several hours.
All told, the recent earthquakes are the strongest to hit Italy since 1980, when a 6.9-magnitude earthquake and its aftershocks killed 3,000 residents.
According to Paolo Spagna, with Italy's National Council of Geologists, all three sets of earthquakes were part of the same seismic event.
"You have energy that builds up and causes an earthquake, and if the earthquake does not dissipate all that energy, it starts to build up again," he told Xinhua.
"When that happens, you get a new series of earthquakes," Spagna said.
And there is no sure way to tell if a fourth round of earthquakes is around the corner or, if it is, when it might hit and how strong it will be, he said.
"It all depends on whether the energy that had been building up along the major fault line in central Italy is finally used up.
"But, I would have to guess that with the strength of these recent earthquakes, more might be on the horizon," Spagna said.
Predicting earthquakes with accuracy is nearly impossible, but some Italians thought it should be easier.
In 2009, six Italian geologists and one civil servant were found guilty of manslaughter after downplaying risks of an earthquake six days before a deadly 6.3-magnitude earthquake that flattened much of the city of L'Aquila, east of Rome.
The conviction was overturned only in 2014.
Italy has been periodically struck by serious earthquakes. The historical record includes relatively detailed information for major earthquakes dating as far back as the year 1,117, when a 6.5 magnitude quake left 30,000 dead near the northern Italian city of Verona.
The deadliest quake in the modern era struck the city of Reggio Calabria -- the toe of Italy's boot-shaped peninsula -- and across the narrow Straights of Messina to northern Sicily in 1908, killing more than 100,000.
The strongest quake to strike Italy in the last 1,000 years was a 7.4 tremor that pounded eastern Sicily in 1693.
With such a history of seismic activity, Italians in earthquake-prone areas learn to live with the risks.
Salvatore Mazza, an earthquake expert with the National Institute of Geophysics and Volcanology, said it's important for residents to reinforce their homes and other buildings.
"It's a question of retrofitting the house to make it more resilient," Mazza said in an interview.
"You can never reduce the risks to zero, but properly retrofitted buildings usually suffer only slight damage."
Spagna said residents in at-risk areas should be vigilant and ready to flee any time.