Destroyed cars are seen in the rubble after an earthquake in Finale Emilia. A strong earthquake rocked a large swathe of northern Italy early on Sunday, killing at least three people and causing serious damage to the area's cultural heritage. Photo: Reuters

Two new strong aftershocks rattled north-east Italy overnight on Thursday, sending people outdoors and further damaging buildings hit by a weekend earthquake, local officials said.

The aftershocks struck around midnight (22.00 GMT) with the first one measuring 4.3 and the second 3.2, and local media said a total of 18 aftershocks had hit the area during the night.

“The fear has returned,” said Fernando Ferioli, mayor of the Finale Emilia town that was worst hit by Sunday's quake that killed six people and left thousands homeless.

“We're taking a step backwards and as long as there isn't a bit more calm we won't be able to get out of the situation.

“We're trying to convince people to return to their homes if these haven't been damaged, but if the aftershocks continue, this will be impossible,” he said, adding that crews have been working to secure damaged buildings since dawn.

The makeshift dwellings set up in the aftermath of Sunday's quake are completely filled and entire families camped the night in their cars following the aftershocks, he said.

The “red zone” that the authorities established in the centre of the city, prohibiting access because of a high risk of damaged buildings collapsing, has been enlarged again on Thursday after being reduced the previous day, he said.

The Italian government on Tuesday declared a 60-day state of emergency in the region hit by the quake and promised 50 million euros ($63 million) in aid to help rebuild houses and family-owned factories.

Sunday's quake has led 6 000 people to camp out in temporary shelters. - Sapa-AFP