A 175-acre fire was burning in the Norco area Tuesday, fueled by brush and light winds.
The so-called Mann Fire began burning around 10 a.m. at California Avenue and Grulla Court in Norco.
A large plume of smoke could be seen for miles in the area.
Evacuations were order north of North Drive from Crest View to California Avenue.
By noon, evacuations were expanded to include North of 8th Street, East of Pedley Avenue and South of Santa Ana Riverbottom.
It was 20% contained by 11:20 a.m.
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A battalion chief at the scene described the wildfire as "well established'' with the potential to expand to 1,000 acres if unchecked, wire services said.
It wasn't clear what had initially ignited the blaze.
By 4 p.m., Cal Fire Riverside officials said forward progress had stopped, and there was minor damage to fencing on some properties.
Evacuation centers were set up at Corona High School, 1150 W. 10th St., and Jurupa Valley High School, 10551 Bellegrave Ave.
Norco has been known as "Horsetown USA" since 2006.
Large animals like horses can be temporarily evacuated to Ingalls Equestrian Event Center at 3737 Crestview Drive.
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