Last week, Italy had reported just three confirmed cases of the virus.

At the weekend, this number spiked dramatically.

The head of Italy’s civil protection department, Angelo Borrelli, said 152 people had now tested positive for the virus, including three deceased.

The new cases are mostly in the northern Lombardy region, which is one of Italy’s most densely populated areas.

Italy became the first country in Europe to announce a death from coronavirus on Friday, when a 78-year-old man died in the Veneto region.

A 77-year-old cancer patient infected with the coronavirus died in Lombardy on Saturday, while another elderly woman died from the infection in Crema on Sunday.

The first deaths from the virus in Italy prompted new security measures by the government to contain the spread of infection.

Regional and municipal authorities throughout Italy enforced a series of restrictive ordinances after the government issued emergency measures late on Saturday.

Eleven towns – 10 in Lombardy and one in Veneto – are now under lockdown, with residents forbidden from leaving after a cluster of cases emerged in the town of Codogno, around 60 kilometres southeast of Milan.

“We invite people to stay at home, to try and contain this phenomenon that we still don’t know, except that it isn’t aggressive but moves quickly,” Giulio Gallera, the official responsible for health for the Lombardy region, said during a televised news conference on Sunday.

At least 50,000 people are affected by the lockdown.

Regional authorities have cancelled all public events such as sporting matches, and instructed schools to remain shuttered.

Many other venues in Lombardy, aside from those providing essential services, have been closed, including museums, most bars, night clubs and movie theatres, as well as churches.

In some other regions, similar closings took place.

In Milan, mayor Giuseppe Sala announced that schools would be closed for a week.

At least two trade fairs in the Lombard city were postponed to a later date, though most of the shows for Milan Fashion Week continued on schedule.

Italian designer Giorgio Armani held his show behind closed doors, to an empty room, live-streaming the event instead.

Carnevale is one of Venice’s major annual festivities and the cancelling of events has disrupted the plans of many visitors who had flocked to the city before Tuesday’s final Mardi Gras celebration.

“Maximum precaution has been taken to protect citizens,” Prime Minister Giuseppe Conte of Italy wrote on Twitter Sunday.

Two military structures in Lombardy were being converted into isolation camps, while other military sites and hotels have been identified throughout the country.

A military base in Rome has been housing evacuees from the Wuhan province in China, the epicentre of the virus, and the Italian passengers of the Diamond Princess, the cruise ship that has been under quarantine in Yokohama, Japan.

The outbreak in northern Italy began after a 38-year-old man known as “patient one” was admitted and diagnosed with the virus to Codogno’s hospital on Thursday.

But the patient had developed symptoms perhaps five days before that, potentially allowing the virus to spread.

Even more disconcerting is that health officials still don’t know how he contracted the virus because he had not been to China.

But many cases in Lombardy, officials say, may be traceable to that one case.

At least five members of the hospital medical staff in Codogno and several patients have been infected.

Other persons who tested positive include the man’s pregnant wife, a close friend, and others who spent time with them.