The Warner Bros. movie studio has been hit with an outbreak of COVID-19.

The Burbank, California-based studio, known for blockbusters like “Dune” and the “Batman” and “Matrix” franchises, reported a sudden jump in COVID as cases in Los Angeles hit their highest weekly average of new cases since last summer’s Delta surge.

The studio reported 43 cases as of Tuesday to the LA County Department of Public Health, according to reports. It is likely those numbers have climbed since then. A rep for the studio declined to comment.

The spike in new infections comes just one month after Warner Bros. began requiring employees to return to the office at least three days a week.

Warner Bros., which has one of the bigger lots, is not the only Hollywood studio to see a COVID outbreak. According to the Los Angeles Times, on Tuesday Disney and Fox Sports reported six and 10 new cases, respectively, among their employees. In May, Lionsgate reported 21 new infections.

The trove of new cases coming out of Hollywood studios, and LA overall, come as the county expects to shift into the “high” level on the US Centers for Disease Control and Prevention’s COVID-19 community level tracker, the newspaper said. As of Thursday, the CDC said LA County remained at a “medium” level, but that status could change if cases continue to rise.

If it moves into the “high” level for two consecutive weeks, the county is prepared to reinstate its indoor mask mandate as soon as July 29. Media insiders believe that mandate could come down before the end of this week.

At a meeting of the LA County Board of Supervisors on Tuesday, County Public Health Director Barbara Ferrer said the county is experiencing its first jump in COVID-19 deaths since the winter surge, the LA Times reported.

“While we’re not seeing anywhere near the devastation this summer that we saw during last winter’s Omicron surge, we are seeing much higher case numbers than we saw during the peak of the Delta surge,” Ferrer said.

The increase in coronavirus infections has experts concerned, particularly as employees continue to return to the workplace. LA officials are urging employers with three or more COVID cases within a two-week period to consider encouraging employees to work from home when possible.