WINCHESTER, Calif. -

A fire that broke out Monday near Winchester blackened about 500 acres and left 2 firefighters with minor injuries, but no homes or other structures were threatened.

Full control of the fire was expected by Tuesday evening at 6 p.m.

The blaze was reported around noon at Vista and Rawson roads, according
to the Riverside County Fire Department.

A firefighter suffered minor injuries at the start of the fire, then later in the afternoon a second firefighter was taken to the hospital.

Twenty-eight engine crews, two water tender crews and eight inmate hand crews -- numbering about 220 personnel -- were working to encircle the blaze.

Four water-dropping helicopters and four air tankers were making runs on
the brusher, according to the fire department.

Firefighting resources were assigned to remain on scene throughout the night watching for any flare ups or hot spots.

There was no immediate word on what sparked the blaze.