SONOMA COUNTY (CBS SF) — Cal Fire crews in the North Bay are at the scene of a vegetation fire burning near the community of Schellville Wednesday afternoon, according to authorities.

Crews from the Sonoma-Lake-Napa Cal Fire Unit were headed to the so-called Fremont Fire near Fremont Drive and Napa Road in the unincorporated community of Schellville close to the Napa-Sonoma County line as well as the burn scar left by the Nuns Fire in 2017.

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The fire was also causing some traffic delays on Highway 121 heading west due to smoke.

The Cal Fire LNU Twitter account posted about the incident at around 2:30 p.m.

As of around 3:30 p.m., the fire had grown to 40 acres, according to Cal Fire. Both Cal Fire and Napa County Fire were providing air support with planes and helicopters dropping water and fire retardant.

The Napa County Sheriff advised that smoke may be visible in the area, but no other threats have been identified and no evacuations have been ordered.

By 5 p.m., an assistant fire chief with the Schellville Fire Department said that the fire had grown to over 50 acres. There were some reports that the fire had gotten as large as 100 acres.

Residents in the area are advised to stay indoors and close your doors and windows to prevent smoke from entering your home.

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Residents and people traveling in the area were advised to use caution.