Rescue workers ended their search for survivors of a second killer earthquake in northeastern Italy on Wednesday, as local industry faced losses worth millions of euros.

While aftershocks as large as 3.8 magnitude continued to shake the shocked region, thousands of jittery survivors fearful of further tremors stayed close to camps where they had sought shelter.

Tuesday's quake centred 60 kilometres (35 miles) east of Parma killed 17 people and injured 350 just nine days after a similar disaster in the same region killed six and left thousands homeless.

As the dust settled, tired and miserable evacuees said they could not take it anymore.

"It's like living through the war again... We're constantly frightened there will be another big quake," said Ester, 89, who has been in a tent camp since the first quake on May 20 along with hundreds of other desperate people.

"Until yesterday, we had hope. People had begun to work in the factories again... but the new earthquake knocked us flat," her daughter Serenella said.

Italy's Confindustria association in Modena said the damage caused by Tuesday's quake was likely to cost 500 million euros ($622 million), while the Coldiretti farming association gave a similar figure for the agricultural sector.

The financial fallout for the heavily industrialised region is a sevre blow for debt-ridden Italy, which entered into recession at the end of last year.

The government said it was suspending taxes in the areas affected and would try to reboot the economy by lowering interest rates on loans.

Wednesday morning found shocked residents gaping in dismay at collapsed houses, historic buildings with gaping holes in their sides and razed churches in once picturesque towns scattered across the countryside near Modena.

"Everything happened so fast, in about seven to eight seconds. I don't even remember. I'm grief-stricken, speechless. I have no tears left to shed," said one worker who gave his name as Daniel and three of whose colleagues died.

Those among the weary, dust-covered evacuees who failed to find a place in the government's overflowing emergency tent camps set up rickety shelters in gardens or slept in cars or on park benches, unwilling to go back indoors.

Others bunked down in specially-prepared train carriages.

"We're more comfortable here compared to other places, it's better, safer," a frazzled-looking Hussein Mzhar from Pakistan said, after spending the night on board a train with his brother, sister-in-law and two children.

Mzhar said he had been at home when the quake hit: "It was scary, everything was damaged in the house but thanks to God my life is rescued. I've no idea on how many nights we will be in the train."

Residents in cities across northern and central Italy from Pisa to Venice rushed into the streets in panic when the quake struck at 0700 GMT, as many were arriving for work.

Panicking people broke down as they failed to get through to loved ones on their mobile phones as telephone lines jammed, while others gazed in horror at the traumatic damage to beloved monuments.

Italy's newspapers were again filled with shocking images, such as the church in the quaint town of Cavezzo, which stood derelict with its roof caved in.

Exhausted workers called off their searches after recovering the body of the last missing person from the ruins of the Haematronic factory in the town of Medolla, where three other workers had been found dead on Tuesday.

As the region took stock of the damage to national heritage treasures, there were calls for an investigation into why the wreckage was so extensive.

Prosecutors in Modena said they will open an inquiry into the number of factory buildings which collapsed.

The region's economic base has been hit hard by both quakes, with producers of the renowned Parmasen cheese and balsamic vinegar from Modena paying a heavy price, with stocks worth millions of euros lost.

"The real epicentre of the earthquake has been the world of work," Labour Minister Elsa Fornero told the Italian Senate on Wednesday.

Authorities said 8,000 people were displaced by Tuesday's quake, adding to the 6,000 residents already living in makeshift dwellings since the May 20 6.0-magnitude quake.

At a camp set up at a school in San Felice sul Panaro, survivors stood huddled together for comfort or seeking shade from the searing summer heat.

"I've heard we could be here until the end of the summer. We're worried we're going to be abandoned," said 68-year-old Adriana.