Residents in the area have been asked to voluntarily leave their homes.
Halifax Regional Police Staff Sgt. Bill Morris said between 50 and 100 people have left their homes and traffic is being diverted.
Morris said a specific location was named in the threat, but he declined to make that location public.
A K-9 unit has been sent to the area.
CBC News has placed phone calls to several businesses in the affected area and none have answered the phone.