LOS ANGELES — The mayor of Los Angeles urged 4 million residents to wear masks to combat the coronavirus when they walk out in public, even as state health officials shied away from requiring a coverup.

Homemade cloth masks, or even a “tucked-in bandanna,” will help reduce the spread of the COVID-19 virus in the nation’s second-largest city and remind people to practice safe social distancing, Mayor Eric Garcetti said Wednesday as he donned a black cloth mask to make his point.

I know this looks surreal,” Garcetti said. “We’re going to have to get used to seeing each other like this … This will be the look.”

But he urged people against using medical-grade masks, such as N95 or surgical masks, which are in short supply and needed for health care workers and first responders. Garcetti also said people should only use masks when they are going out to shop for food or perform other essential tasks.

Otherwise, stay home, the mayor said.

“This isn’t an excuse to suddenly all go out,” Garcetti said.

California’s 40 million people are under state and local orders to stay at home except when performing essential tasks. Health experts have said that is the best way to slow the spread of the virus, which as of Wednesday had infected nearly 10,000 Californians and caused 215 deaths, according to Johns Hopkins University, which is keeping a global tally.

Los Angeles County Reported More Than 500 New Cases on Wednesday

Gov. Gavin Newsom has said the number of COVID-19 cases in California is expected to peak in late May.

The spread of the virus statewide has, so far, been slow enough to give the state time to prepare for an expected spike in cases that could overwhelm hospitals if extreme measures aren’t taken to keep most people home and away from others.

Los Angeles County reported more than 500 new cases on Wednesday, a 17% hike over the previous day.

The mayor’s non-binding mask recommendation followed a similar recommendation on Wednesday for residents of Riverside County, east of Los Angeles County.

County public health officer Dr. Cameron Kaiser urged that people who need to go out in public should use something — even neck warmers — to cover their mouths and noses to protect others and themselves from infected droplets from coughs or sneezes.

However, California’s public health officials released guidance Wednesday on the use of cloth masks that specifically didn’t require their use.

While the non-medical face coverings might provide some additional protection, “Californians should not have a false sense of security if they choose to wear them,” Health and Human Services Secretary Dr. Mark Ghaly said. “Make sure you’re also staying 6 feet away from other people if you have to leave your home to get groceries or prescriptions.”

Mask Recommendations Have Been Issued in Some Countries but They’re by No Means Universal

“Face coverings are not a substitute for physical distancing or frequent hand washing, which we know are amongst the most effective ways to reduce the spread of COVID-19,” Dr. Sonia Angell, state public health director, said in a statement.

Earlier in the day, Angell said cloth masks could be a pitfall because if handled or worn incorrectly they might lead to infection and also might make people feel “somewhat immune” and relax their social distance.

Mask recommendations have been issued in some countries but they’re by no means universal. The World Health Organization has recommended people caring for a sick relative wear a mask. The U.S. Centers for Disease Control and Prevention agreed — as long as the person who was ill was not able to wear a mask.

But there has been some conflicting direction. Austria said this week it would require masks for grocery shoppers. President Donald Trump suggested people who are worried should wear a scarf.

For most people, the coronavirus causes mild or moderate symptoms, such as fever and cough, that clear up in two to three weeks. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia and death.