The powerful tremors which shook central Italy on Wednesday were the product of a new earthquake rather than aftershocks from one that devastated the town of Amatrice in August, Italian experts say.

"It wasn't an aftershock, it was a new earthquake," Mario Tozzi of the national institute for environmental geology and geo-engineering (IGAG) told AFP.

"What we do not know is whether it was a dormant section of the Amatrice fault or a parallel structure, a close cousin of this fault," he added.

Tozzi said Wednesday's 'double-hit' quake, in which an initial tremor of 5.5 magnitude was followed by one of 6.1, was typical of the central Appenine mountains.

He recalled the 1997 Assisi earthquake in which four workers were killed when a second shock struck while they inspecting buildings damaged the previous day.

"In the coming months we can expect a series of after shocks but they should get progressively weaker," Tozzi said, while stressing it was impossible to rule out another major quake in the short term.

Much of Italy's land mass and some of its surrounding waters are prone to seismic activity with the highest risk concentrated along its mountainous central spine.

Nearly 300 died in the Amatrice disaster in August and just over 300 perished when a quake struck near the city of L'Aquila in 2009.

In 1980 tremors near Naples left 3,000 dead and an estimated 95,000 in the 1908 Messina disaster, when a quake in the waters between mainland Italy and Sicily sent massive waves crashing into both coasts.

Italy straddles the Eurasian and African tectonic plates, making it vulnerable to seismic activity when they move.

The movement of the plates is slowly pushing the country northwards at a rate which, experts predict, could result in it becoming attached to what is now Croatia in around 20 million years time.

Nightmare recurs on Italy's earthquake frontline
Ussita, Italy (AFP) Oct 27, 2016 - "It's never ending. These damned earthquakes won't leave us alone!"

As she distributes pastries, hot coffee and juice to the traumatised residents of Ussita in the early hours of the morning, restaurateur Linda Cappa expresses the prevailing mood in this quake-prone Italian village after its latest brush with disaster.

Located in the mountainous interior of the Marche region, Ussita was close to the epicentre of two powerful shocks that shook a large swath of Italy on Wednesday evening.

Elderly villager Bruno recounted how he had headed straight for his car as soon as the first one struck. Experience had told him he had to get out of his house.

"The second one was much, much stronger than the first," he said. "It seemed like it was going to go on for ever.

"I thought my car was going to be turned over. It's a disaster. What on earth is going on under our feet?"

Situated at just above 600 metres (around 2,000 feet), Ussita is home to around 300 people.

Although no deaths were reported, Wednesday's tremors did significant damage and left the area's population in shock once more, two months after nearly 300 people died in another quake centred closed to the nearby town of Amatrice.

The village's mayor Marco Rinaldi described "apocalyptic" scenes of people running into the streets screaming.

"The lights went out, our village is finished," he said a few hours later as he prepared to chair a crisis meeting of rescue workers in a tent hastily erected in the middle of the village.

The winding road that leads up to the village was strewn with stones and debris that had tumbled down the mountainside.

- Cards and cigarettes -

Numerous buildings looked like they have been hit by bombs, others had collapsed completely.

Aftershocks, some powerful, some just strong enough to provide a reminder of the big ones, rumbled repeatedly throughout the night.

The villagers have got used to feeling the earth move beneath them, having been shaken by thousands of aftershocks since the August 24 quake, which left nearly 300 people dead.

"We are a bit used to this now," says Cappa with an air of weary resignation.

On the edge of the village, Red Cross staff have re-established tents they first put up in August, housing around 100 of the village's 300 residents.

Some smoke anxiously, others play cards to pass the time. A few try to get some sleep on camp beds.

"It is the one place they feel safe," said Alessandra Franconi, a volunteer helping the aid effort who says the rest of the village's inhabitants have either opted to sleep in their cars or headed for a local campsite.

Wooden huts alongside the tents have been there since 1997, when they served as accommodation for victims of a previous earthquake before later housing a temporary village school.

Another resident, Sergio, is feeling anxious about what the arrival of daylight will reveal.

"I have no idea what state I am going to find my house in. We'll see. The only thing I hope is that it did not collapse on top of anyone."