Update 3.10pm: Italy's civil protection agency has upgraded the provisional death toll from Italy's 6.1-strength earthquake to 73.
Update - 11.40am: At least 38 people have died in the magnitude 6 earthquake that struck central Italy, according to Italy's civil protection agency.
Update - 10.45am: At least 23 people are reported dead after an earthquake rocked central Italy, collapsing homes on top of residents as they slept.
Rescue crews raced to dig survivors out of the rubble, but the toll is expected to rise as rescuers reached homes in more remote hamlets.
Earlier: A strong earthquake has struck central Italy, collapsing homes on top of residents as they slept.
At least 11 people were reported dead in two hard-hit towns, where rescue crews raced to dig out survivors from the rubble.
"The town isn't here anymore," Amatrice mayor Sergio Pirozzi said.
The magnitude 6 quake struck at 3.36am local time (1.36am Irish Time) and was felt across a broad swathe of central Italy, including the capital, Rome, where residents felt a long swaying followed by aftershocks.
The hardest-hit towns were Amatrice and Accumoli near Rieti, some 80 miles (100km) north-east of Rome, though the quake was felt beyond the Lazio region into Umbria and Le Marche on the Adriatic coast.
The centre of Amatrice was devastated, with entire palazzos razed to the ground. Rocks and metal tumbled on to the streets and dazed residents huddled in piazzas as dozens of aftershocks continued into the early morning hours, some as strong as 5.1.
"The whole ceiling fell but did not hit me," said resident Maria Gianni. "I just managed to put a pillow on my head and I wasn't hit, luckily, just slightly injured my leg."
As daylight dawned, residents, civil protection workers and even priests began digging out with shovels, bulldozers and their bare hands, trying to reach survivors. There was a sigh of relief as a woman was pulled out alive from one building, followed by a dog.
"We need chainsaws, shears to cut iron bars, and jacks to remove beams: everything, we need everything," civil protection worker Andrea Gentili told the Associated Press.
The devastation harked back to the 2009 quake that killed more than 300 people in and around L'Aquila, which sent emergency teams to help with the rescue on Wednesday.
The Italian geological service put the magnitude at 6.0. The US Geological Survey put the magnitude at 6.2 with the epicentre at Norcia, about 105 miles (170km) north-east of Rome, and with a relatively shallow depth of six miles (10km).
"I don't know what to say. We are living this immense tragedy," said the Rev Savino D'Amelio, an Amatrice parish priest. "We are only hoping there will be the least number of victims possible and that we all have the courage to move on."
The mayor of the quake-hit town of Accumoli, Stefano Petrucci, said at least six people had died there, including a family of four, and two others.
"There are deaths," he told state-run RaiNews24.
In Amatrice, the Ansa news agency reported that two bodies had been pulled from one building.
The Rev. Fabio Gammarota told Ansa another three were killed in a separate collapse.
Amatrice Mayor Pirozzi told state-run RAI radio and Sky TG24 that residents were buried under collapsed buildings, that the lights had gone out and that heavy equipment was needed to clear streets clogged with debris.
The office of Premier Matteo Renzi tweeted that heavy equipment was on its way.
In 2009, a 6.3-magnitude earthquake struck in the same region and killed more than 300 people.
The earlier earthquake struck in L'Aquila was about 55 miles (90km) south of the latest quake.
A 1997 quake killed a dozen people in the area and severely damaged one of the jewels of Umbria, the Basilica of St Francis in Assisi, filled with Giotto frescoes. The Franciscan friars who are the custodians of the basilica reported no immediate damage from Wednesday's earthquake.