Los Angeles County in the western US state of California has made face masks mandatory at outdoor "mega events" amid a resurgence of coronavirus infections.
More cities across the US are requiring people to wear masks in outdoor public settings. The Los Angeles County masking requirement for large outdoor concerts, sporting and other events with more than 10,000 attendees came into effect on August 19.
Los Angeles County does not require masks at small outdoor theaters. But on Friday, many people wore face coverings at a theatrical performance with an audience of about 200 people in response to calls by the organizers.
One person in the audience said masks aren't comfortable but they can help protect the local community. Another said it's safer for everyone to wear masks.
Anyone violating the mask requirement faces a fine of up to 1,000 dollars.
The western state of Oregon has also begun requiring masks again at outdoor events since Friday.