More wildfires started in Southern California on Tuesday night and Wednesday, as gusty Santa Ana winds continue to plague the state this week.

The Clay fire, which broke out Tuesday in a river bottom in Riverside County east of Los Angeles, quickly spread to nearly 40 acres. But by Tuesday night, crews had stopped its progress and were doing “extensive mop-up operations,” Riverside officials said. It was 40 percent contained as of 4 a.m. Wednesday, according to Cal Fire.