Los Angeles county on Friday announced a temporary ban on gatherings of people from different households under a new "safer-at-home order" triggered by a spike in Covid-19 cases, with religious services and protests exempt.
The order affecting the United States' second-largest city will take effect Monday and last at least three weeks, until December 20, the county's public health department said.
"In the new Order that goes into effect on Monday, residents are advised to stay home as much as possible," said a statement.
"All public and private gatherings with individuals not in your household are prohibited, except for faith based services and protests, which are constitutionally protected rights," it added.
Densely populated Los Angeles county has suffered over 7,600 coronavirus deaths -- more than a third of California's fatalities -- although Covid-19 is increasingly prevalent in the Golden State's remote rural areas.
California last week imposed a night-time curfew across much of the state, while Los Angeles county on Wednesday barred dining at restaurants but allowed delivery to continue.
The order comes as Los Angeles county's average new daily cases passed 4,500 for the week, triggering the tougher measures.
The "safer-at-home" measures are not as severe as the city's first lockdown in March, which saw almost all businesses close their physical premises.
But the new order reduces occupancy limits at various businesses that can remain open, including shops, spa and libraries.
All schools can remain open unless they record outbreaks.
"These targeted measures are in effect for the next three weeks and still allow for many essential and non-essential activities where residents are always masked and distanced," said public health director Barbara Ferrer.
"We know we are asking a lot from so many who have been sacrificing for months on end and we hope that L.A. County residents continue following Public Health safety measures that we know can slow the spread."