One of the fundamentals for searching for a bomb is not to touch a suspicious object. On discovery of a questionable article, the searcher then needs to alert persons nearby to leave the area. The next step is to notify the Security Chief (if one is there in office) or local police station. The other responsive actions that can follow include:

•  Questioning employees who may be able to account for the presence of the suspicious object.
•  Ordering a partial or full evacuation
•  Notifying the Police Control Room
•  Notifying the Fire Station
•  Opening the doors or windows for the purpose of dissipating the blasts
•  Establishing traffic control around the facility to regulate free movement of emergency vehicles.

Putting up large solid objects, sand bags around the suspect object could help contains the damage. But this requires judgment & risk taking as the object can explode at any moment. Due to unpredictable nature of such package, it is advisable to leave such risks to professionals or law enforcement agencies