Fumes were reported at 750 Pelham Parkway and Holland Avenue in the Pelham Parkway section just before 1 p.m.
FDNY officials say an illegal grow house was found in the first-floor apartment of a six-story building.
Three occupants of two apartments above had to be evacuated.
No injuries have been reported.
NYPD, Hazmat, Con Edison and BFI are on the scene investigating.
Operations are ongoing.
This story will be updated as more information becomes available.
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