A powerful earthquake rattled a remote area of central Italy on Wednesday, leaving at least 120 people dead and scenes of carnage in mountain villages.
With 368 people injured and an unknown number trapped under rubble, the figure of dead and wounded was expected to rise in the wake of the pre-dawn quake, Prime Minister Matteo Renzi warned.
"This is not a final toll," he said.
Hundreds of people were to spend a chilly night in hastily-assembled tents with the risk of aftershocks making it far too risky for them to return home.
Scores of buildings were reduced to dusty piles of masonry in communities close to the epicentre of the quake, which had a magnitude of between 6.0 and 6.2.
It comes as urgent inquiries are being made in Rome to work out if any Australians are caught up in the disaster.
"The Australian Embassy in Rome is making urgent inquires with local authorities to establish whether any Australians have been affected," a Department of Foreign Affairs and Trade spokesman said.
" If you have any concerns for the welfare of family and friends in Italy you should attempt to contact them directly."
If contact cannot be made, phone DFAT's 24-hour Consular Emergency Centre on 1300 555 135 or +61 2 6261 3305 if calling from overseas.
Dozens of buildings collapsed in communities close to the epicentre of the quake in a remote area straddling the regions of Umbria, Marche and Lazio.
Deaths were reported in the villages of Amatrice, Accumoli and Arquata del Tronto as residents and emergency services scrambled frantically to rescue people trapped beneath the ruins of houses reduced to piles of masonry.
It was Italy's most powerful earthquake since 2009, when more than 300 people died in and around the city of Aquila, just to the south of where Wednesday's quake struck.
"The situation is dramatic, there are many dead. I cannot give a toll for now because rescue efforts are under way and it is very, very difficult," said Amatrice mayor Sergio Pirozzi.
"Half the village has disappeared."
Fabrizio Curcio, the head of Italy's civil protection service, classed the quake as "severe". The shocks were strong enough to wake residents of central Rome, some 150 kilometres away.
The first two confirmed victims were an elderly couple whose home collapsed in Pescara del Tronto, a hamlet near Arquata in the Marche region.
Aleandro Petrucci, the mayor of Arquata, said Pescara was one of "two or three hamlets that have just completely disintegrated."
Another two people died and a family of four including two young children were trapped, feared dead, in their collapsed house in Accumoli, according to its mayor Stefano Petrucci.
"We have a tragedy here," Petrucci said.
"There are people under the ruins, it is not a good situation."
A resident of the village told Rai television that she had been woken by the shaking in time to witness the wall of her bedroom cracking open. She was able to escape into the street with her children.
Amatrice, where the local authorities confirmed five deaths, was packed with visitors at the peak of the summer season when the quake struck, destroying the hilltop village's main street.
Mayor Pirozzi said difficult access to the village had prevented emergency services getting through.
"There is a landslide on one road, a bridge is about to collapse on the other one," he said.
"We can hear voices under the rubble."
Amatrice is famous in Italy as a beauty spot and is a popular holiday destination for Romans seeking cool mountain air at the height of the summer.
The first quake struck shortly after 3.30am (11.30am AEDT), according to the United States Geological Survey, and a 5.4-magnitude aftershock followed an hour later.
USGS's PAGER system, which predicts the impact of earthquakes, issued a red alert -- suggesting significant casualties and damage based on previous quake data.