Crews have surrounded 40% of the 211-acre Sun Fire burning in the hills between Lompoc and Gaviota, according to Cal Fire‘s update on Friday night.

The fire was reported at 12:15 p.m. Thursday in the 7200 block of Highway 1, according to the Santa Barbara County Fire Department. 

Large plumes of smoke were visible throughout the area, including from wildfire cameras, on Thursday.

Ground crews and firefighting aircraft responded to the scene, including several air tankers with a second alarm called.

The blaze blackened more than 200 acres, officials said Thursday. 

On Friday morning, about 100 firefighters remained assigned to the incident with 20% containment achieved, county fire Capt. Scott Safechuck said. 

Firefighters expected to continue working at strengthening and improving containment lines, Safechuck added. 

However,  incident commanders were wary since windy and low-humidity conditions were expected Friday.

No structures were threatened by the fire. 

The cause of the blaze remained under investigation on Friday, officials said.