Some evacuation orders were issued in the Mead Valley region of Riverside County on Wednesday due to a fast-growing brush fire. 

The Rider Fire, which was first reported just before 5:30 p.m. near Rider Street and Seaton Avenue, west of the 215 Freeway, has burned nearly 50 acres, according to the Riverside County Fire Department. 

Four Cal Fire air tankers and two water-dropping helicopters joined hand crews as they attempted to control the flames, which briefly threatened at least one structure, firefighters said. 

As the fire burned, firefighters issued evacuation orders and warnings for people living on Old Elsinore Road. Several roads were also closed due to the firefight. 

All evacuations have since been lifted and crews are expected to remain at the scene overnight to continue strengthening containment lines, Cal Fire said. 

No injuries have been reported and no structures are believed to have been damaged. 

The cause of the fire remains under investigation.