(Bloomberg) --

America’s most infected metropolitan area may be shutting down outdoor dining again -- and could even face a three-week lockdown.

The Greater Los Angeles area added 4,522 new coronavirus cases Saturday, bringing the four-day total to 17,769, county data showed. Another 2,231 cases Sunday would bring the five-day average to 4,000, hitting the threshold for additional measures where restaurants, breweries and bars would once again limit their businesses to just pick-up and delivery.

“We have to change the alarming increases in cases and hospitalizations and get back to slowing the spread to avoid overwhelming our hospitals and save lives,” Barbara Ferrer, director of public health for Los Angeles County, said in a statement Saturday.

Saturday’s case count brought the total for the Greater Los Angeles area to 361,879, the highest among counties in the U.S. -- and exceeding those in nations including Canada, Saudi Arabia, Austria and China, where the outbreak was thought to have started.

The Los Angeles area, with a population of about 10 million, had imposed additional measures starting Friday night, including limiting capacity for retail stores, offices and restaurants. Non-essential shops and restaurants must also close from 10 p.m. to 6 a.m., except for takeout, delivery and pick-up.

Even more stringent curbs will follow if Sunday’s new cases reach 4,731. That will bring the five-day average to 4,500, which could trigger a three-week “Safer at Home” order, its version of a lockdown that comes with more restrictions, allowing largely “essential and emergency workers and those securing essential services to leave their homes.” The hospitalization of more than 2,000 a day would also lead to the order.

Ahead of the Thanksgiving break, officials across the U.S. have urged residents to avoid travel and scale back gatherings -- or cancel them altogether. Los Angeles Mayor Eric Garcetti tweeted Saturday to remind residents to celebrate virtually or only with members of the same household.

The concerns were escalated as California reported 15,442 new coronavirus cases Saturday, hitting a high as the state’s overnight curfew kicked in. The total number of infections has increased to almost 1.1 million. The 10 p.m.-to-5 a.m. curfew will be imposed in most counties for a month, affecting areas that encompass 37 million people, or 94% of the population.

©2020 Bloomberg L.P.