Spot fires in the bed of the Santa Clara River created a plume of smoke over the center of Santa Clarita Wednesday night.

Arson was suspected.

The Los Angeles County Fire Department responded with a full brush fire assignment just before 7 p.m., according to Imy McBride, a department supervisor.

A little after 8 p.m. the fire, near the intersection of Bouquet Canyon Road and Soledad Canyon Road, had grown to 3 acres.

Sheriff’s deputies detained one arson suspect, according to Sgt. Adam Stoll with the Santa Clarita Valley Sheriff’s Station.

“They’re actively still investigating to determine if her or she is involved in any kind of arson,” he said.

Stoll said deputies were actively searching for any additional suspects. They were also working with the L.A. County Fire Department to determine the cause of the fire.

As part of their search for additional suspects, sheriff’s deputies set up a containment area near Newhall Ranch Road and Bouquet Canyon Road, including the wash on both sides of Bouquet Canyon Road.

The containment area extended to the William S. Hart PONY baseball fields down to McBean Parkway, Stoll said.

This story was last updated Wednesday, May 19 at 8:49 p.m.

Los Angeles County Fire Equipment lines up along Valencia Boulevard. Dan Watson / The Signal.

Sheriff set up containment on bike paths around fire area. Dan Watson / The Signal