ROME — Four regions in Italy are being put under severe lockdown, forbidding people to leave their homes except for essential reasons, in an effort to slow surging COVID-19 infections and prevent hospitals from being overwhelmed.

Premier Giuseppe Conte on Wednesday night announced what he described as “very stringent” restrictions on the so-called “red zone” regions of high risk: Lombardy, Piedmont, Valle d’Aosta in the north and Calabria, the region forming the “toe” in the south of the Italian peninsula.

Except for few circumstances, no one will be allowed to enter or leave “red zone” regions or even travel between their towns, although people can exercise by themselves and while wearing masks near home. Non-essential stores will be closed, although barber shops and hair salons can stay open, and only nursery, elementary and the first year of middle school will have in-class instruction.

Conte said the lockdown will begin Friday to allow time to organize. Designations will be reviewed every two weeks.