Police patrolled a popular nightlife area of Milan on Friday, a day after hordes of young people gathered without protective masks during cocktail hour, flouting social distancing rules.

Italian authorities have feared that an easing of the country's two-month lockdown could encourage more social gatherings, putting at risk progress made in stemming the spread of the coronavirus which has killed over 30,000 people in the country.

Newspapers on Friday carried images of crowds of young Milanese, many without masks, sitting and chatting in groups, or strolling together along the city's canals during the early evening on Thursday.

That prompted a rebuke from Milan's mayor, Beppe Sala, who called the behaviour "shameful," and gave the city an ultimatum -- either start respecting social distancing rules or newly opened bars and cafes offering take-out service would be closed.

Citizens appeared to have got the message.

On Friday, amid a strong police presence, most in the area wore masks and appeared to be following the rules.

One woman, Michela Lacancellera, 41, said she preferred the lower-key atmosphere on Friday.

"Yesterday I went out with my children and I did not feel safe," she said. "Today I feel more comfortable because there's a tenth of the people compared to yesterday."

People stroll along the Navigli canals in Milan where police were on patrol to ensure they respected social distancing norms amid fears of a coronavirus resurgence as Italy, one of the worst affected country, eases its strict lockdown rules
People stroll along the Navigli canals in Milan where police were on patrol to ensure they respected social distancing norms amid fears of a coronavirus resurgence as Italy, one of the worst affected country, eases its strict lockdown rules AFP / Miguel MEDINA

Gregorio Mancino, 57, said the police presence had deterred partygoers.

But, he added, the risk of crowds gathering was everywhere.

"This problem not only concerns the Navigli (canals) area but also other areas where everyone has left the house just like here," Mancino said.

Prime Minister Giuseppe Conte has warned that restrictive measures could be reinstated throughout the country if people do not act responsibly in "Phase 2" of the coronavirus emergency, in which people are allowed to circulate more freely and more businesses are allowed to open, while still respecting social distancing and avoiding gatherings.

"If you love Italy, keep your distance," Conte said during a televised address ahead of the loosening of restrictions on May 4.

Earlier Friday, a renowned local virologist, Massimo Galli, warned that Milan was "a bit of a bomb," with a high risk of new infections, given the number of formerly infected people now circulating in the populous city.

Lombardy, of which Milan is the capital, has logged nearly 15,000 deaths, around half of Italy's approximately 30,000 coronavirus fatalities, since the outbreak first erupted in early March.

Over the weekend, more than 1,000 police officers will be on duty in Milan to patrol, especially in parks, to ensure that people are respecting the restrictions, authorities said.

Coronavirus Medicine