Firefighters in Riverside County are battling a wildfire that erupted in a Santa Ana river bottom Monday night that’s threatening structures and has prompted an evacuation warning. The Clay Fire, which was first reported at 5 p.

Jurupa Valley fire crews are back on scene battling a brush fire in the Santa Ana River bottom, after having extinguished a blaze in a similar location last week.

Clay Fire initially started today at 4:59 p.m. in Riverside County. Since its discovery less than an hour ago, it has burned three acres of private land, an increase of two acres since the last update. At this time, there is no information on the containment of the fire and the cause of it remains undetermined.