Thousands of people huddled out of doors in northeastern Italy after the region's second killer earthquake in less than two weeks and officials warned of more aftershocks.

Tuesday's quake killed at least 16 people and injured 200 just nine days after another temblor killed six people and left thousands homeless.

Residents in cities including Pisa and Venice rushed into the streets in panic when the quake struck 60 kilometres (40 miles) east of Parma at 0700 GMT on Tuesday.

Just a few hours later, already shaken residents endured a terrifying five-minute ordeal when the region was struck by three tremors of between 5.1 and over 5.3 magnitude between 1056 GMT and 1101 GMT.

By nightfall authorities said one person remained missing.

The grim search through the rubble was launched in the small town of Medolla after muffled cries for help were heard from beneath the debris of damaged buildings, SKY TG24 television said.

Workers at a destroyed precision mechanics factory near Modena where three of their colleagues died, meanwhile, told how they ran for their lives as the ground shook beneath them, ripping the building in two and sending masonry crashing to the ground.

"Everything happened so fast, in about seven to eight seconds. I don't even remember. I ran out carrying the piece I was working on and I saw everything crumble," said one worker who gave his name as Daniel.

"The quake was so violent," he said, trembling with shock, adding that he feared being trapped in the shaking building.

As the dust began to settle in the moments following the quake, those who had made it to safety realised that three people -- an Italian, as well as an Indian and a Moroccan called Kumar and Mohammed respectively -- had been killed in the collapse.

"I'm grief-stricken, speechless. I have no tears left to shed," Daniel added, explaining that he had worked with the dead men at the close-knit Meta factory in San Felice sul Panaro for years.

One of the two victims had been living in a tent at a camp since the earlier 6.0-magnitude quake on May 20.

That quake killed six and left around 7,000 people in makeshift tent dwellings, with many homes and historic buildings reduced to rubble.

The Italian Civil Protection Authority said 16 people died in the latest quake and Antonio Catricala, Italy's cabinet undersecretary, said around 200 people had suffered injuries on Tuesday.

"I have to leave the building, we're being hit by a long, powerful tremor. I have to get out," a civil protection agency spokesman in Mantua told AFP as one of the tremors struck.

"Everything's collapsed, it's chaos, buildings across the town are down," a fireman in the tiny town of Cavezzo told Corriere della Sera newspaper earlier.

Authorities in the Emilia Romagna region said over 5,000 people had been evacuated from their homes and emergency places arranged for 4,000 homeless.

"Last night was the first night we'd spent back in our homes after the first quake. Then another one hit," one resident told SKY TG24 television in Sant'Agostino, scattered with buildings with gaping holes in their sides.

Among the quake victims was a parish priest in the town of Rovereto di Novi who was killed by a falling beam, reportedly after he went back into his church to save a Madonna statue.

Dust filled the air in the picturesque towns of Carpi and Concordia, while in Mirandola rubble covered the Duomo floor and the roof gaped open to the sky.

In Mantua, the Ducal Palace -- famous for a stunning collection of frescoes in the Wedding Room -- was damaged, along with a number of historic churches.

"A new quake has hit the Emilia Romagna region, leaving victims, wounded people and damaged buildings in its wake," Prime Minister Mario Monti said in a televised address from Rome.

Pope Benedict XVI sent his condolences to the families of the victims of Tuesday's quake which was felt throughout northern and central Italy.

The region has been hit by a series of quakes and aftershocks over the past two weeks. Authorities have registered at least 800 tremors since May 20.

The latest disasters struck just over three years after a 6.3-magnitude quake devastated the city of L'Aquila in central Italy in March 2009, killing some 300 people and leaving tens of thousands homeless.