ROME — At least 20 people died and thousands were left homeless when an earthquake with a magnitude of 6.3 shook central Italy early Monday morning, seriously damaging buildings in the mountainous Abruzzo Region east of Rome, officials told Italian news media.

The epicenter was in L’Aquila, a picturesque Medieval fortress hill town, where eight people died and more were trapped under rubble, officials said.

The situation is “extremely critical, as many buildings have collapsed,” Luca Spoletini, a spokesman for Italy’s Civil Protection Agency, told the ANSA news agency. Prime Minister Silvio Berlusconi declared a state of emergency in the region.

The quake struck around 3:30 a.m. and could be felt as far away as Rome, some 95 miles to the west, where it rattled furniture and set off car alarms.

Several buildings in L’Aquila were reduced to rubble.

Electricity, phone and gas lines were also reported damaged, as aftershocks continued.