A 6.5-magnitude earthquake hit central Italy on Sunday, causing no victims, but destroying precious historic buildings.

It was the fourth strong seismic event since late August, and the most powerful quake in the country since 1980, when a similar strike destroyed Irpinia area south of Naples, according to officials.

The temblor hit some 5.5 km from Norcia, a famous medieval town in the Umbria region, at 07:40 a.m. local time (0640 GMT). The epicenter was at a depth of 10 km, the Italian National Institute of Geophysics and Volcanology (INGV) reported.

No casualties were reported on Sunday. Some 20 people were injured, but none of them were in critical conditions, Italian civil protection's chief Fabrizio Curcio told a press conference.

"We are going to face a tough night. Yet, this (absence of victims) is a great news we have," Curcio said.

"We are now focused on providing first assistance to all those who had to leave their houses, waiting to later move them in hotels and other hosting structures along the Adriatic coast," he added.

The overall number of displaced people was not yet available, but anyway "significant", according to the official.

Earlier this week, the same areas had been hit by two temblors measuring a magnitude of 5.4 and 5.9, respectively.

On Aug. 24, another 6.0-magnitude earthquake had struck villages and towns of central Lazio and Marche regions, only slightly to the south from Sunday's epicenter. That first temblor killed 298 people, and injured some 400 others.

After such sequence, the number of people forced to leave their homes might now amount to several tens of thousands, according to authorities.

"This latest 6.5 quake has changed the scenario and the scale of the emergency," Curcio stressed. "We need time to adjust our assessment, but we will keep following the path of close coordination with local and regional authorities we have undertaken since Aug. 24."

Authorities and relief teams also explained the absence of victims in such a strong quake had been possible thanks to one of the main factors: many people had already left their houses after the previous temblors earlier this week.

Although no victims were claimed, the event proved disastrous for already deeply affected communities in central Italy.

People were under much strain, as the earth has kept trembling for months. Indeed, the INGV has registered some 18,000 aftershocks since Aug. 24.

Some 15,000 power lines were cut, and many roads in central Italy were disrupted, according to the civil protection authorities. A main highway connecting Rome to the affected areas was cut off due to landslides, and some provincial roads were impassable, creating difficulties for relief efforts.

Several buildings were severely hit, and other structures already damaged by the two previous earthquakes this week, including the 14th-century San Benedetto Basilica in Norcia, were almost flattened.

The Cathedral of Santa Maria Argentea also collapsed during the quake.

"We will rebuild everything," Prime Minister Matteo Renzi said.

He appealed to the local population to "not resign," despite the much pain, fatigue, and stress they were going through.

The prime minister also encouraged mayors to submit to the government action plans to upgrade building safety standards in their towns and also outside the directly affected areas.

"We will accept no restraint, these areas must be reconstructed because they represent the heart of Italy," Renzi added.

Sunday's quake was strongly felt in Rome, some 170 km west to the epicenter. The metro service was shut down to allow precautionary checks. No severe damages were reported as of Sunday, but schools would remain close on Monday to check on their infrastructures.

The temblor was also felt as far as in the northern city of Bolzano, near the border with Austria, and in the southern region of Puglia.

A 6.5-magnitude earthquake hit central Italy on Sunday, causing no victims, but destroying precious historic buildings.

It was the fourth strong seismic event since late August, and the most powerful quake in the country since 1980, when a similar strike destroyed Irpinia area south of Naples, according to officials.

The temblor hit some 5.5 km from Norcia, a famous medieval town in the Umbria region, at 07:40 a.m. local time (0640 GMT). The epicenter was at a depth of 10 km, the Italian National Institute of Geophysics and Volcanology (INGV) reported.

No casualties were reported on Sunday. Some 20 people were injured, but none of them were in critical conditions, Italian civil protection's chief Fabrizio Curcio told a press conference.

"We are going to face a tough night. Yet, this (absence of victims) is a great news we have," Curcio said.

"We are now focused on providing first assistance to all those who had to leave their houses, waiting to later move them in hotels and other hosting structures along the Adriatic coast," he added.

The overall number of displaced people was not yet available, but anyway "significant", according to the official.

Earlier this week, the same areas had been hit by two temblors measuring a magnitude of 5.4 and 5.9, respectively.

On Aug. 24, another 6.0-magnitude earthquake had struck villages and towns of central Lazio and Marche regions, only slightly to the south from Sunday's epicenter. That first temblor killed 298 people, and injured some 400 others.

After such sequence, the number of people forced to leave their homes might now amount to several tens of thousands, according to authorities.

"This latest 6.5 quake has changed the scenario and the scale of the emergency," Curcio stressed. "We need time to adjust our assessment, but we will keep following the path of close coordination with local and regional authorities we have undertaken since Aug. 24."

Authorities and relief teams also explained the absence of victims in such a strong quake had been possible thanks to one of the main factors: many people had already left their houses after the previous temblors earlier this week.

Although no victims were claimed, the event proved disastrous for already deeply affected communities in central Italy.

People were under much strain, as the earth has kept trembling for months. Indeed, the INGV has registered some 18,000 aftershocks since Aug. 24.

Some 15,000 power lines were cut, and many roads in central Italy were disrupted, according to the civil protection authorities. A main highway connecting Rome to the affected areas was cut off due to landslides, and some provincial roads were impassable, creating difficulties for relief efforts.

Several buildings were severely hit, and other structures already damaged by the two previous earthquakes this week, including the 14th-century San Benedetto Basilica in Norcia, were almost flattened.

The Cathedral of Santa Maria Argentea also collapsed during the quake.

"We will rebuild everything," Prime Minister Matteo Renzi said.

He appealed to the local population to "not resign," despite the much pain, fatigue, and stress they were going through.

The prime minister also encouraged mayors to submit to the government action plans to upgrade building safety standards in their towns and also outside the directly affected areas.

"We will accept no restraint, these areas must be reconstructed because they represent the heart of Italy," Renzi added.

Sunday's quake was strongly felt in Rome, some 170 km west to the epicenter. The metro service was shut down to allow precautionary checks. No severe damages were reported as of Sunday, but schools would remain close on Monday to check on their infrastructures.

The temblor was also felt as far as in the northern city of Bolzano, near the border with Austria, and in the southern region of Puglia.