MESA, Ariz. (AP) — The Maricopa County Sheriff's Office says a brush fire near the Salt River has shut down part of a Bush Highway. Sheriff's officials say the highway near northeast Mesa has been closed in the area southeast of Red Mountain after the fire jumped the road Tuesday evening. The fire is continuing to grow due to wind gusts of nearly 30 mph. It's estimated to have burned nearly 25 acres and is burning through salt cedar trees. Sheriff's officials say no structures are threatened at this time and the cause of the fire is unclear.