FILE - A fire burns in Shasta County, California, Aug. 22, 2019, in this image obtained via social media. In Riverside County, a wildfire threatened hundreds of homes Thursday.
FILE - A fire burns in Shasta County, California, Aug. 22, 2019, in this image obtained via social media. In Riverside County, a wildfire threatened hundreds of homes Thursday.

MURRIETA, CALIFORNIA - Hundreds of homes were evacuated and schools closed Thursday as crews battled a stubborn wildfire churning through heavy brush in Southern California.

The blaze near the Riverside County city of Murrieta and unincorporated community of La Cresta grew to more than 2 square miles (5.4 square kilometers) and was 7% contained, authorities said.

There were no reports of structure losses.

"There's lots of heavy fuel in very steep terrain that we can't get to on foot," said Capt. Fernando Herrera with the California Department of Forestry and Fire Protection. Aircraft were making continuous drops of water and retardant, he said.  

More than 480 homes were in the mandatory evacuation zone and another 2,270 are under voluntary evacuation orders, according to Herrera.

The blaze erupted Wednesday afternoon on rural land and erratic winds quickly pushed flames down hills toward homes about 70 miles (115 kilometers) southeast of Los Angeles.

The cause may have been a lightning strike as hot, muggy weather produced thunderstorms. Those conditions will continue into Friday, the National Weather Service said.

It's one of a number of fires burning around the state. There's very little containment of a 1.5-square-mile (3.9-square-kilometer) blaze in rural forest land along the northern Sierra Nevada in Plumas County.