Italy's prime minister has said at least 16 million people are in mandatory quarantine in the Lombardy region and also in 14 provinces.
The lock-down will last until early April.
The dramatic escalation in the country's efforts to contain the new coronavirus will close gyms, pools, museums and ski resorts.Italy is Europe's worst-hit country and reported a steep rise in virus infections on Saturday.
The new measures, which also apply to financial centre Milan and tourist hotspot Venice will last until 3 April.The death toll in Italy has passed 230, with officials reporting more than 50 deaths in 24 hours. The number of confirmed cases jumped by more than 1,200 to 5,883 on Saturday.