At least 27 people, including several children, have been killed after a strong earthquake destroyed thousands of buildings in central Italy, police say.
Silvio Berlusconi, the Italian prime minister, declared a state of emergency after the magnitude 6.3 quake struck near the city of L'Aquila, in the mountainous Abruzzo region east of Rome, early on Monday morning.
"Thousands of people [could be left] homeless and thousands of buildings collapsed or damaged," Agostino Miozzo, an official at the civil protection ministry, said.
Local news agencies reported that people were feared trapped under the rubble and rescue services have been deployed to the area.
Guido Bertolaso, head of Italy's public safety department, said there would be "numerous victims, many injured and so many collapsed homes," the ANSA news agency reported.
"It's an event that will mobilise the nation for many weeks."
Part of a university residence and a church tower were among the buildings that had collapsed in L'Aquila, officials said.
Television footage showed rubble blocking streets in the town and burying several parked cars.
Massimo Cialente, the mayor of L'Aquila, told Sky Italia television that two people were reported dead in the small town of Fossa. He said that eight others were missing in the town of San Demetrio dei Vestini.
He said that about 100,000 people had left their homes and many buildings in the L'Aquila's historic centre were damaged.
"The civil defence department is setting up some sort of tent town where they will be housed until the situation with their homes is made clearer," Sabina Castelfranco, a Rome-based journalist, told Al Jazeera.
"People are walking around draped in blankets, they have been up all night."
Antonio D'Ostilio, one resident of L'Aquila, said: "We left as soon as we felt the first tremors.
"We woke up all of a sudden and we immediately ran downstairs in our pyjamas."
Electricity supplies to about 15,000 people were cut, while part of the highway linking L'Aquila to Rome was closed, ANSA news agency reported.
According to the US Geological Survey, the epicentre of the earthquake was about 95km northeast of Rome, at a depth of about 10km.
It struck 3:32am (01:32 GMT) when many people were asleep.
The earthquake was the latest and strongest in a series that have shaken the area since Sunday.
It came just hours after a magnitude 4.6 tremor shook Italy's north-central region, with no reports of damage.
Italy is criss-crossed by two fault lines, with about 20 million people at risk from earthquakes.
In October 2002, 30 people, including 27 pupils and a teacher, were crushed under a school in the tiny village of San Giuliano di Puglia during an earthquake.
Twenty-two years earlier, on November 23, 1980, a violent quake struck the southern region of Irpiona near Naples, killing 2,570, injuring 8,850 and displacing 30,000.