A magnitude 6.2 earthquake has struck central Italy, leaving at least 21 people dead and many others trapped under rubble, reports say.
Many of the dead were in the village of Pescara del Tronto which was levelled to the ground and there were fears the number could rise.
Much of the town of Amatrice was reduced to rubble and a family of four were feared dead nearby in Accumoli.
The quake hit at 03:36 (01:36 GMT), 100km (65 miles) north-east of Rome.
Although it struck at a shallow depth of 10km, its intensity was compared to the Aquila earthquake in April 2009 in which 309 people died. The epicentre was around Accumoli where several people died.
Some buildings in the capital shook for 20 seconds as the quake struck an area between the regions of Umbria, Lazio and Marche. It was felt from Bologna in the north to Naples in the south.
The highest casualties were reported in the small village of Pescara del Tronto, where 10 people were reported dead, among them children. Twenty people have been taken to hospital.
Two boys aged four and seven were pulled alive from the rubble of the house they had been staying in with their grandmother, Ansa news agency reported. Rescuers said they had been sheltering under a bed.
More damage was reported a short distance up the road in Arquata del Tronto.
Some of the worst damage was in the town of Amatrice, where at least five died and rescue efforts were under way to find survivors.
“The roads in and out of town are cut off.
Half the town is gone. There are people under the rubble. There’s been a landslide and a bridge might collapse,” said mayor Sergio Pirozzi.
“There are tens of victims, so many under the rubble. We’re preparing a place for the bodies,” he said.
In Accumoli, a short distance to the north, Mayor Stefano Petrucci said one person had been pulled out of the rubble during the night.
“Then there is a family of four under a collapsed house and sadly there are two small children among them.”
A local photographer spoke of 15 rescuers digging with their bare hands trying reach the family.
Seismologist Andrea Tertulliani said there were sure to be further, numerous shocks that would probably diminish in intensity.
“But it can’t be ruled out that there could be another shock on the same scale as the main one,” he said.
“They hear the screams of the mum and one of the children,” he said.
The main street through the town has been devastated and emergency workers are trying to reach six people in a collapsed building.
Italy’s Civil Protection agency described the earthquake as “severe”.
“It was so strong. It seemed the bed was walking across the room by itself with us on it,” Lina Mercantini of Ceselli, Umbria, told Reuters.
Rescue teams are being sent to the worst-hit areas, the prime minister’s office said.