Three people were lightly injured by falling masonry during the quake, which struck at a depth of around 5.0 kilometres (3.1 miles), while one person suffered a heart attack and was hospitalised.
The quake hit two kilometres (just over a mile) from the walled city of Fivizzano in the province of Massa and Carrara in Tuscany, sparking panic among residents who rushed out of houses onto the streets.
Seismologist Marco Mucciarelli from the national experimental oceanographic and geophysics institute told SKY Italia television that tremors felt in Venice and across the top of Italy around the same time were not the same quake but aftershocks.
"There are likely more to come," he said, adding that there were "big problems with communication" in the towns and cities near the epicentre of the quake, slowing efforts to check damage caused.
The quake lasted just a few seconds, according to witnesses speaking to local journalists.
Damage to houses was limited to Tuscany and Emilia Romagna, while a historic bell tower in the small town of Regnano suffered a partial collapse.
The civil protection agency's regional office in Tuscany said it was sending a thousand camp beds to the town of Casola in Lunigiana, where authorities and volunteers were setting up a tent camp for residents unable or too afraid to sleep indoors.
In the city of Reggio Emilia, Italy's Equal Opportunities Minister Josepha Idem cut short a speech as the quake hit and the town hall she was in was evacuated.
Local trains across the region were interrupted but the fast train from Milan to Bologna was running without disruption, according to Italy's rail service.
Fear of earthquakes in the region is high after two powerful quakes wrecked homes and businesses in the neighbouring Emilia Romagna region in May 2012, killing 25 people.