PERRY HALL, Md. (WJZ) — Hazmat crews are on the scene of a suspicious package in Perry Hall.

Baltimore County fire officials got the call just before 4 p.m. Thursday.

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A package containing an unknown substance was found in a mailbox on Perry Hall Boulevard.

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Authorities say it was delivered by the United States Postal Service.

A similar incident happened about a month ago in the same area.

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Residents are being evacuated from the building as a precaution.