Rescuers are still searching for survivors as dozens of aftershocks continue to plague the area hampering their efforts.
TV footage showed rescuers racing away from the rubble of a ruined house as a tremor hit, sending masonry flying.
Gianfranco Fini, speaker of Italy's lower house of parliament, said entire towns had been "virtually destroyed" with 15,000 buildings off limits.
The epicentre was close to the city of L'Aquila in the centre of Italy, about 100 miles northeast of Rome.
The village of Onna, close to L'Aquila, was "wiped off the map" with no houses left standing, according to one emergency official.
In the fields outside, row after row of coffins were lined up and officials said at least 50 of the 400 inhabitants are dead.
The tremor struck at just after 3.30am local time and measured 6.3 on the Richter scale.
Prime Minister Silvio Berlusconi cancelled a visit to Moscow and immediately flew to the scene, calling the area a "disaster zone".