LOS ANGELES (AFP) — About 24,000 people remained under evacuation orders Monday as a wind-driven wildfire spread near Reno, Nevada, forcing schools to close and threatening homes.

The Hawk Fire had burned more than 15,000 acres (6,000 hectares) since starting Saturday. Firefighters had contained 27 percent of its perimeter, officials said.

More than 40,000 people were under evacuation orders at the fire’s peak, while thousands more remained on alert.

No deaths have been reported, but seven people were injured, including three first responders. At least 32 properties were destroyed.

More than 900 firefighters were battling the blaze, assisted by crews from across the United States, Australia and New Zealand.

Truckee Meadows fire chief Richard Edwards said the fire was “human caused,” but investigators have yet to determine whether it was intentional.

“The Hawk Fire is a very dynamic incident for us as it’s being driven by the winds. The wind-driven fires move very rapidly into our residential areas,” Edwards said.

Reno Mayor Hillary Schieve urged residents under evacuation orders to leave immediately.

“If you have been told to evacuate, please don’t wait!” she said.