MILAN, Italy: Venice was inundated by an exceptionally high tide on Monday, with three-quarters of the famed city under water as large areas of Italy experienced flooding and winds that toppled trees and other objects, killing six people.

Tourists and residents wore high boots to navigate the streets of Venice after strong winds raised the water level 156 centimetres before it receded.

The water exceeded the raised walkways normally put out in flooded areas in Venice, forcing their removal. Transport officials closed the water bus system, except to outlying islands, because of the emergency.

Venice frequently floods when high winds push in water from the lagoon, but Monday's levels were exceptional. The peak level was the highest since December 2008, according to Venice statistics.

Venice mayor Luigi Brugnaro said a series of underwater barriers being erected in the lagoon would have prevented the flooding. The project, nicknamed Moses, is long delayed, beset by cost overruns and corruption scandals.

Brugnaro said he had asked to talk with Premier Giuseppe Conte to underline the urgency of the project, which would raise barriers when the tide reaches 109cm. That happens, on average, four times a year in Venice.

High winds also toppled trees that killed passers-by in four incidents in Naples, Lazio and Liguria.

Officials closed major tourist attractions early in Rome, including the Colosseum and Roman Forum, because of heavy rain.