A wind-driven brush fire that broke out Thursday in the Santa Ana River bottom in Riverside charred 10 acres as crews worked to encircle the fire before it reached residential areas lying in its path.
The blaze was reported at 4:50 p.m. in the area of Mission Inn Avenue and Crestmore Road, initially within the Riverside city limits, according to the Riverside Fire Department.
Multiple engine and hand crews from both Riverside and Riverside County converged on the location and encountered flames in thick brush, moving at a moderate rate to the east.
By 6 p.m., the fire was approaching homes and camps in both Riverside and Jurupa Valley, prompting requests for a Cal Fire water-dropping helicopter, according to reports from the scene.
There was no word on potential evacuation orders.
The river bottom is dotted with dozens of homeless encampments, but it was not immediately known whether the blaze was human-caused.