Los Angeles County, the most populous in the US, has reported a record single-day increase in the number of new Covid-19 cases for the first time since the summer surge in July.
A total of 3,780 new cases and 20 new deaths were reported on Saturday, Xinhua news agency quoted the Los Angeles County Department of Public Health as saying in a statement.
"This marks the highest amount of positive cases in one day, not associated with a backlog of cases, since mid-July," the statement said, adding that the elevated number of cases reflects increased testing across the county.
Officials said that over 56,000 tests were processed on Friday, and the positivity rate remains high at almost 6 per cent.
The department has identified 336,549 positive cases countywide and a total of 7,266 deaths to date.
There were 966 people currently hospitalized with Covid-19, and 28 per cent of them are in the ICU, officials said, noting that current hospitalization "is the highest it has been in nearly two months."
Younger people continue to drive the increase in community transmission in the county.
Over 74 per cent of the new cases reported on Saturday are from people under 50 years of age, while 90 per cent of reported deaths on the day are the over-50s.
Officials noted that the rise in cases complicates planning for increasing the numbers of students returning to schools, further re-opening additional sectors and permitting additional activities.
Both Los Angeles County and the state of California are experiencing a surge in new cases.
Authorities of California said Friday cases in the state have surpassed 1 million, becoming the second US state to reach the grim milestone.