Demolition of a mill in Stalybridge that was severely damaged by fire could take five to six weeks.
Tameside Council is urging the public to comply with the safety cordon while the demolition of Ray Mill takes place.
The structure is said to be unstable and extremely dangerous after being ravaged by a fire, which started last Saturday night.
The council says although most of the fire is now extinguished, the root of the fire is deeply embedded in layers of rubble so it will only be fully extinguished as demolition work takes place.
As a precaution all nearby residents and businesses are advised to continue to keep their doors and windows closed to prevent any smoke from the remaining fire from entering their homes.
The site is being treated as a potential crime scene and police and fire officers are investigating as they gain safe access to the building.