VALLEJO (CBS SF) — A large grass fire was burning near homes and highways in Vallejo Wednesday afternoon.

Two separate fires were reported at 3:40 p.m. in marshland near the junction of Highways 37 and 29, Vallejo fire spokesman Mark Libby said. Authorities have closed the south connector from Highway 29 to westbound Highway 37.

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One of the fires reportedly began at a homeless encampment. The other was touched off by a structure fire. The fire department combined both calls into one response.

Flames spread to between 5 and 10 acres and were burning close to homes on Sonora Pass Road.

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Firefighters have set up defensively to stop the fire from spreading to the structures, Libby said.

Light to moderate winds were blowing in the area, fueling the fire and making it difficult to contain.

Assistance has been called from surrounding areas including Crockett, American Canyon and Solano County. A Cal Fire helicopter is making drops on the fire, Libby said.

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