Again Los Angeles County on Sunday began requiring people to wear masks in indoor public places, opening a new battle line as the coronavirus is rising significantly among unvaccinated people.

SOUTH PASADENA, CA - JULY 18: Lilian Zhu, 17, is working at her laptop wearing her face mask inside Charlie's Coffee House during the coronavirus pandemic on Sunday, July 18, 2021 in South Pasadena, CA. Once again the Los Angeles County on Sunday began requiring people to wear masks in indoor public places, opening a new battle line as the coronavirus is rising significantly among unvaccinated people. L.A. County is by far the biggest jurisdiction in the nation to require masks again. But with coronavirus cases rising across the nation largely because of the highly infectious Delta variant, officials elsewhere will be watching to see if the effort works. (Francine Orr / Los Angeles Times via Getty Images)