San Francisco, Sep 9 (IANS): A deadly wildfire in Southern California that killed two people has tripled in size in just 24 hours, exploding from about 5,000 acres to over 18,600 acres, authorities said.

The fast-moving Fairview Fire started on Monday afternoon near the city of Hemet in Riverside County amid a brutal heatwave, reports Xinhua news agency.

Only 5 per cent of the blaze has been contained so far, according to the Riverside County Fire Department.

The fire has forced a series of evacuation orders and road closures in the area.

Around 2,500 structures are still under threat as over 1,100 firefighters, with aircraft support, are continuing their efforts against the wildfire.

Officials said that at least seven structures have been destroyed and several more have been damaged by the blaze.

The two victims of the fire have not been identified, but Riverside County fire officials believe they were trying to escape the flames in a canyon.

Their bodies were found in a burned car, and authorities believe they were related, local media reported.

"That area is a one way in, one way out. So if you don't leave in time, or if you get trapped by fire, there's no other way to go," California Department of Forestry and Fire Protection captain Richard Cordova was quoted as saying.

Due to the blaze, the Hemet Unified School District announced that all schools will remain closed through the rest of the week.