The quake struck shortly after 3:30 am on Monday, catching residents in their sleep and flattening houses, centuries-old churches and other buildings in 26 cities and towns.
207 people are now confirmed dead in the worst quake to strike Italy in 30 years. Of the approximately 1,500 people injured, about 100 are in serious condition.
Rescuers worked under floodlights through the night. Thousands of people whose homes were wrecked took shelter in tents and cars.
"The hopes of finding anyone under the rubble now are very small," said a civil protection agency official.
Yesterday's aftershock hit at about 11:26 am local time and registered a magnitude of 4.7 on the Richter scale. It was felt as far away as Rome, and hampered chances of finding any possible survivors in the debris.