A mysterious odor prompted the evacuation of more than 100 workers from a Plainview office building Wednesday.

Workers in the building called 911 after a handful of employees complained of an odor, and then headaches. Witnesses estimate six or seven workers were affected by the smell, which some compared to mothballs. Later, police say a Shore Pharmaceutical manager received a phone call claiming someone placed a powder on a coworker's desk.

Police in HAZMAT suits searched the building for an odorous or powdery substance, to no avail. Workers were allowed to return to the building around 2:30 p.m.