Riverside brush fire burns 70 acres near Santa Ana River bottom; all mandatory evacuations lifted

RIVERSIDE, Calif. (KABC) -- Riverside firefighters on Thursday afternoon were contending with a stubborn vegetation fire near the arid Santa Ana River bottom that burned 70 acres and briefly prompted the evacuations of nearby homes, officials said.

According to the Riverside Fire Department, firefighters responded shortly before 10 a.m. to an area near the Santa Ana River Trail and Grand Avenue. No injuries or structural damage were immediately reported.

By 12:30 p.m., the flames had consumed 10 acres. An hour later, the agency reported a "significant increase in fire activity."

A mandatory evacuation order was issued for Old Ranch Road and Park Cliff Court. All evacuation orders were lifted by 2:30 p.m.

The fire 30 percent contained by 4 p.m., officials said.

The cause of the fire is unknown.