RIMANEWS-An earthquake in northern Italy has killed at least four people and caused serious damage to buildings in several towns, officials say.
The 6.0-magnitude quake struck in the middle of the night, about 35km (22 miles) north of the city of Bologna.
The officials say the three of the victims died when the buildings they were working in collapsed.
Italian TV showed damaged factories and church steeples in the region. Aftershocks have been reported.
Rescue teams are now combing the area amid reports that a number of people may be buried under rubble.
The earthquake struck at a relatively shallow depth of 10km just after 04:00 local time (02:00 GMT).
It was felt across a large swathe of northern Italy, including the cities of Bologna, Ferrara, Verona and Mantua.
The tremor forced many terrified residents into the streets.
Two people were killed in Sant'Agostino when a ceramics factory collapsed.
The mother of one of the victims told local media that "he wasn't supposed to be there. He changed shifts with a friend".
Another person - believed to be a Moroccan national - was killed in Ponte Rodoni do Bondeno.
A woman died near Bologna, with reports suggesting that she may have had a heart attack.
About 50 people were injured - but none seriously, reports say.
"I was woken at around 4am by the quake, it was strong and lasted up to a minute, maybe more," Frankie Thompson, a UK travel journalist in Bologna, told the BBC.
"Church bells were set off spontaneously... followed by an eerie silence. Small aftershocks kept coming and going until maybe 5:50am when a stronger tremor shook us again but not as long and dramatic as the first," she added.
One local resident told Ansa: "I heard a big bang and I ran on the terrace, I was afraid of falling."
TV footage later showed people inspecting damaged houses, offices and historic buildings. Parts of a fortress in one town reportedly collapsed.
Emergency officials ordered the evacuation of patients from hospitals as a precautionary measure.
Northern Italy is frequently rocked by minor earthquake, but the country is well-prepared to deal with them, the BBC's Alan Johnston in Rome reports.
In January, a 5.3-magnitude quake hit northern Italy but caused no injuries.
The last major tremor to hit the country killed nearly 300 people in the central town of L'Aquila in 2009.[ach/BBC]