SAN JOSE (CBS SF) — Fire crews in the South Bay are battling a San Jose brush fire Thursday that has been giving firefighters a challenge for a couple of hours.

At least two acres have burned so far. The fire is sending up a large plume of smoke over East Capitol Expressway.

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Chopper 5 crews out there still dealing with pockets of flames.

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The fire burned right up to some backyards of homes nearby.

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Investigators believe the fire may have started at a nearby homeless camp, but are still looking into the cause.