Authorities in northern Italy on Friday ordered the closure of schools, bars and other public spaces in 10 towns following a flurry of new coronavirus cases.
Five doctors and 10 other people tested positive for the virus in Lombardy, after apparently frequenting the same bar and group of friends, with two other cases in Veneto, authorities said at a press conference.
Over 50,000 people have been asked to stay at home in the areas concerned, while all public activities such as carnival celebrations, church masses and sporting events have been banned for up to a week.
Italian Prime Minister Giuseppe Conte said "everything is under control", and stressed the government was maintaining "an extremely high level of precaution".
Streets in the towns were deserted, with only a few people seen abroad, and signs showing public spaces closed.
In Casalpusterlengo, a large electronic message board outside the town hall read "Coronavirus: the population is invited to remain indoors as a precaution".
The first town to be shuttered was Codogno, with a population of 15,000, where three people tested positive for the virus, including a 38-year old man and his wife, who is eight months pregnant.
Three others there have tested positive to a first novel coronavirus test and are awaiting their definitive results.
Codogno mayor Francesco Passerini said the news of the cases "has sparked alarm" throughout the town south of Milan.
The 38-year old, who works for Unilever in Lodi, was in a serious condition in intensive care.
He had dined earlier this month with a man who had visited China in January, and had later shown flu-like symptoms, but has since tested negative for the virus, Italian media said.
A football friend of his, the son of a bar owner in Codogno, has also tested positive, along with three regulars at the bar.
The three, all of whom are retired, live in the small town of Castiglione d'Adda. The mayor there said the locals were "extremely worried" about the spread of the deadly disease.
Some 250 people were being placed in isolation after coming into contact with the new cases, according to the Lombardy region, and 60 worker at Unilever have been tested for the virus.
Trenord regional railway said its trains would no longer be stopping in three stations in the affected area.
The head of the Veneto region, Luca Zaia, said a 78 and 67-year old, from the village of Vo' Euganeo, at the foot of the Euganean Hills near Padua, had tested positive.
He said "a sanitary ring" would be created around the village, where public spaces would be closed.
Three other cases of the virus in Italy are being treated in isolation at the Spallanzani Institute in Rome.
The outbreak of the so-called COVID-19 illness, which began in December has killed more than 2,200 people and infected more than 75,500 in China.
Over 1,150 people have been infected and eight have died across 26 other countries, according to the World Health Organization.