One of Rome's most historic bridges was closed on Wednesday as the swollen Tiber River roared through the capital and flooded outlying neighborhoods.
The Tiber's muddied waters rose to fill some of the supporting arches of the Ponte Milvio, or Milvian Bridge, threatening to engulf a pedestrian walkway and submerging trees.
The bridge, whose current version dates to 1850, marks the spot of a previous bridge where in 312 the emperor Constantine defeated his rival Maxentius in one of the most pivotal battles of ancient Roman history.
High embankment walls protected the rest of central Rome but the Tiber and Aniene rivers broke their banks north of the city, flooding farmland and parts of smaller towns.
In Rome's northern outskirts, drainage pipes, irrigation canals and sewers backed up, flooding streets that feed into the country's main north-south highway and blocking traffic.
Storms that hit northern and central Italy at the weekend caused huge damage, washing out roads and isolating towns in southern Tuscany. Four people died there, including three electric company workers whose car fell off a collapsed bridge.
Farmers' lobby Coldiretti said rain, flooding and landslides in central and northern Italy may have caused up to 100 million euros in damage to agriculture.
The storms whipped the Adriatic on Sunday, causing some of the worst flooding in the past 150 years in the lagoon city of Venice. St Marks' Square and other low-lying areas were under so much water that some tourists were able to swim there.
Officials said the situation in Venice was returning to normal.
A section of the main A-1 north-south highway that had been closed between the Lazio and Umbria regions was reopened to passenger traffic on Wednesday but still closed to heavy vehicles.