Another strong aftershock has rattled quake-devastated central Italy

Updated: 

Another strong aftershock has rattled quake-ravaged central Italy, reportedly causing more damage to crumbled buildings in hard-hit Amatrice.

The US Geological Survey said the aftershock had a preliminary magnitude of 4.7 and Italy's national geological institute put the magnitude at 4.8, saying the 6.28 am tremor on Friday was preceded by more than a dozen weaker aftershocks overnight and followed by another nine in the subsequent hour.

The quake zone has experienced more than 500 aftershocks, some measuring up to 5.1, in the two days since the original pre-dawn quake on Wednesday.

Meanwhile, prime minister Matteo Renzi has pledged new money and aid to rebuild the quake-devastated region amid mounting soul-searching over why seismic-prone Italy continually fails to ensure its buildings can withstand such catastrophes.

Rescuers stand among debris and the bell tower of Amatrice.

A day after the deadly quake killed 250 people, a 4.3 magnitude aftershock sent up plumes of thick grey dust in the hard-hit town of Amatrice.

The aftershock crumbled already cracked buildings, rattled residents and closed clogged roads.

Firefighters and rescue crews using sniffer dogs worked in teams around the hard-hit areas, pulling chunks of cement, rock and metal from mounds of rubble where homes once stood.

Rescuers refused to say when their work would shift from saving lives to recovering bodies, noting that one person was pulled alive from the rubble 72 hours after the 2009 quake in the nearby town of L'Aquila.

Rescue workers search for survivors from the debris of a collapsed building.

"We will work relentlessly until the last person is found and make sure no-one is trapped," said Lorenzo Botti, a rescue team spokesman.

Worst affected by the quake were the tiny towns of Amatrice and Accumoli near Rieti, 60 miles north-east of Rome, and Pescara del Tronto, 15 miles further to the east.

Many were left homeless by the scale of the destruction, their homes and apartments declared uninhabitable. Some survivors, escorted by firefighters, were allowed to go back inside briefly to get essential necessities for what will surely be an extended absence.

"Last night we slept in the car. Tonight, I don't know," said Nello Caffini as he carried his sister-in-law's belongings on his head after being allowed to go quickly into her home in Pescara del Tronto.

Rescuers search for victims beneath destroyed houses.

An official from the town of Amatrice has told the BBC that three British nationals were among the dead.

Foreign Secretary Boris Johnson said on Thursday that a number of Britons had been "affected" by the earthquake and extra staff had been sent to the region to help provide support to nationals in the area.

The Government has offered "any assistance that we can" to the Italian authorities.

Rescuers make their way through destroyed houses following an earthquake in Pescara Del Tronto.

Charitable assistance began pouring into the earthquake zone in traffic-clogging droves on Thursday.

Church groups from a variety of Christian denominations, along with farmers offering donated peaches, pumpkins and plums, sent vans along the one-way road into Amatrice that was already packed with emergency vehicles and trucks carrying sniffer dogs.

Italy's civil protection agency said the death toll had risen to 250 by Thursday afternoon, with more than 180 of the fatalities in Amatrice.

At least 365 others were taken to hospital and 215 people were pulled from the rubble alive since the quake struck. A Spaniard and five Romanians were among the dead, according to their governments.

A firefighter marks a house with paint signaling the end of a search.

There was no clear estimate of how many people might still be missing, and the Romanian government alone said 11 of its citizens were missing.

Renzi authorised a preliminary 50 million euros (£42.7m) in emergency funding and the government cancelled taxes for residents, pro-forma measures that are just the start of what will be a long and costly rebuilding campaign.

He announced a new initiative, "Italian Homes", to answer years of criticism over shoddy construction across the country, which has the highest seismic hazard in Western Europe.

People prepare to spend the night in a makeshift camp set up inside a gymnasium.

But he also said that it was "absurd" to think that Italy could build completely quake-proof buildings.

"It's illusory to think you can control everything," he said. "It's difficult to imagine it could have been avoided simply using different building technology. We're talking about medieval-era towns."

Those old towns do not have to conform to the country's anti-seismic building codes. Making matters worse, those codes often are not applied even when new buildings are built.

Armando Zambrano, the head of Italy's National Council of Engineers, said the technology existed to reinforce old buildings and prevent such high death tolls when quakes struck every few years.

People prepare to spend the night in a makeshift camp set up inside a gymnasium.

While he estimated that it would cost up to 93 billion euros (£79.5bn) to reinforce all of the historic structures across the country, he said targeted efforts in the riskiest areas could be done for less.

"We are able to prevent all these deaths. The problem is actually doing it," he said. "These tragedies keep happening because we don't intervene. After each tragedy we say we will act but then the weeks go by and nothing happens."

Some experts estimate that 70% of Italy's buildings are not built to anti-seismic standards, though not all are in high-risk areas.

Geologists surveyed the damage on Thursday to determine which buildings were still inhabitable, while Culture Ministry teams were fanning out to assess the damage to some of the region's cultural treasures, especially its medieval-era churches.