Related Rule
Netherlands
Practice Relating to Rule 8. Definition of Military Objectives
Section I. Presence of civilians within or near military objectives
The Military Manual (1993) of the Netherlands considers that:
Acts such as the manufacturing and transport of military materiel in the hinterland certainly do not constitute a direct participation in hostilities. In addition, it has to be borne in mind that the fact that civilians are working in, for example, a weapons factory does not convert such an industrial object into a civilian object. Such a case has to be assessed in the light of the definition of a military objective. 
Netherlands, Toepassing Humanitair Oorlogsrecht, Voorschift No. 27-412/1, Koninklijke Landmacht, Ministerie van Defensie, 1993, p. V-5.