Rescuers continued searching for survivors though the night after a powerful aftershock brought two apartment blocks crashing down in the stricken city of L'Aquila, killing one person and causing panic among rescue workers and survivors of Monday's deadly earthquake.
Chunks of masonry fell from other damaged buildings, including parts of the basilica, and the tremor - measured by the US Geological Survey at magnitude 5.6 - was felt as far away as Rome. Within minutes the city resounded again to the scream of sirens as police and rescue workers rushed to the scene.
Meanwhile, rescue workers were preparing to carry out what one called a "surgical operation" on a collapsed building in the centre of L'Aquila in the hope of saving the lives of four missing students as the overall death toll reached at least 235.
Sergio Basti, the Rome fire brigade engineer leading the attempt, said his team aimed to demolish the residence where the students were trapped "bit by bit from the top, like scraping toppings from a pizza". The students' residence has been a focus of the rescue operation since early on Monday, shortly after the earthquake that devastated the city and several of the surrounding towns and villages.
The operation was decided on after rescue workers fixed the location of the four students inside the shattered building. But Basti warned: "We do not know whether they are dead or alive."
He said relatives of the four young people who were sleeping in the residence when the earthquake struck had been briefed on what was going to happen. The relatives had spent much of the day waiting anxiously, and sometimes tearfully, outside the building among reporters, police and firefighters. Two of the missing were brought out alive from the residence early on Tuesday. Yesterday morning, a third student was found dead.
It was the prelude to a day in which the death toll in and around L'Aquila surged higher and the balance shifted perceptibly away from the hope of finding more survivors and towards a more exigent calculation of the risks facing the rescuers.
Silvio Berlusconi, the Italian prime minister, told a press conference in L'Aquila that the search for the living would go on for another 48 hours. But it was clear that in some places the chances of finding survivors alive had already been written off.
Next to the Piazzale Paoli park where a block of flats had collapsed outwards under the force of the shockwaves, an earth mover was vigorously gouging through the rubble in a way that suggested the rescuers no longer feared disturbing survivors.
The "surgical operation" at the students' residence was decided on after the fourth aftershock since midnight threatened to bring it crashing down. A rescue worker was attached to a crane and lifted above the four-storey building to make an inspection. Afterwards, a member of the team said the residence had been further weakened by the aftershocks and was being kept up by just one of its concrete pillars. Even before they struck, huge concrete slabs that had once been floors were hanging menacingly over the rubble below in which the rescuers were searching.
What chances remained of discovering survivors depended on increasingly delicate probing. A few hundred metres from the students' residence, on the other side of a severely cracked bridge, four Spanish rescue workers were taking a break after working through the night.
None of them had slept since the previous morning. They had just emerged from a nearby house after penetrating to the basement. "We are waiting for a special instrument that can pick up vibrations," said Angelina Molina of the Málaga-based voluntary group GEA, as she took a long drag on her cigarette. "It can pick up even the slightest vibration, even that caused by someone scratching his or her nail on a wall," added her colleague Gabriel Leo.
The periodic wail of sirens and occasional clatter of a helicopter notwithstanding, L'Aquila was like a ghost town yesterday.
Berlusconi said: "Other tremors are possible and the message to the population is not to go back home."
By then, however, a few had already dared to do so. Donatella di Sibio, a 33-year-old shop worker, could not bring herself to leave her parrot behind.
"The staircase has partly collapsed. It's dangerous," she agreed as the parrot sat contentedly on its perch in a cage at her feet. Di Sibio had even brought out some parrot food, along with a handful of specially treasured possessions that her mother had stuffed in a plastic bag.
"That was my grandmother," she said, pointing to a sepia photograph sticking out from the bag.
"I've lived there all my life," said Di Sibio, looking at the 18th century building in which she and her parents shared a flat. "We'd just got it done up. We spent a lot of money on restoring it. The work finished last month. And now it's wrecked."
An aftershock with a magnitude of 5.6 shook Central Italy on Tuesday, nearly 48 hours after a major 6.3 quake hit the country.  Earlier in the day, another aftershock of 4.2 was also reported.  The death toll from the quakes has now surpassed 200 with thousands of others injured.  At least one person was killed in the aftershock.

The aftershock caused two apartment blocks to collapse in the city of L'Aquila, and slabs of masonry fell from other damaged buildings. Local media reported that an old church and many houses were also damaged. The shaking was felt as far away as Rome.

Francessco Rocha, the head of the Italian Red Cross, estimated that 20,000 people had lost their homes, and it may be many months before they can return to them.

"The victims so far are 207," said the premier of Italy, Silvio Berlusconi, at a press conference. "Of these victims, 190 have been identified while other 17 remain unidentified, 15 people are missing and there are more than 1,000 injured, 100 of which are in serious conditions," said Rocha.

"Civil protection men are working hard and for the next 48 hours rescuers will search for other survivors," added Berlusconi. "More than 7,000 men are at work. These people risk their lives and I want to congratulate myself with them, they are doing an extraordinary job considering the frequent ground movements complicate rescuing operations. Already 150 people have been extracted and saved from the ruins."

The 6.3-magnitude quake on April 6 is the deadliest quake to strike Italy since November 23, 1980. Nearly 3,000 people were killed in a magnitude 6.8 earthquake that struck Southern Italy in the Irpinia region. At least 10,000 were injured in that earthquake, with over 300,000 being left homeless.