Four Italian regions are being put under “red-zone” lockdown, with severe limits imposed on the circumstances under which people can leave home, Premier Giuseppe Conte announced on Wednesday night.

What he called “very stringent” restrictions begin on Friday for Lombardy, Piedmont and Valle d’Aosta in the north, and for Calabria, which forms the southern toe of the Italian peninsula.

The lockdown is aimed at tamping down a surge in COVID-19 infections and preventing hospitals from being overwhelmed with cases. Lasting at least two weeks, it will involve some 16.5 million of Italy’s 60 million residents and include the country’s financial capital, Milan.

Barring very few exceptions, no one will be able to leave or enter the “red zone” regions. People there must stay home, except to go to work or shop for essentials. They can also exercise near their homes and while wearing masks.

After days of consultations with regional governors, Health Minister Roberto Speranza decided which regions received the “red-zone” designation.

“I know that these choices will mean sacrifices and difficulties, but they are the only way to bend the (contagion) curve,” he said in a statement. “United, we can do it.”

Barber shops and hair salons can stay open, although other non-essential shops in the “red zone” must close.

Less severe restrictions on movement were decided for southern Sicily and Puglia, where people will be able to leave their homes, but can’t travel between towns or regions, and cafes and restaurants can only do takeout and delivery.

While classrooms are open in the rest of Italy except for high schools, which must do remote instructions, in the “red zone,” only nursery, elementary and the first year of middle-school will still have in-class instruction.

The latest crackdown was supposed to start on Thursday, but Conte said it will begin instead on Friday to allow time to organize. Designations will be reviewed every two weeks.

He added that previously announced nationwide measures, like museum closures and an overnight curfew, would also start a day later, on Friday, and last until Dec. 3.

Conte promised that later this week his center-left government would approve more funds to aid businesses crippled by the latest closures.