Related Rule
France
Practice Relating to Rule 35. Hospital and Safety Zones and Neutralized Zones
France’s LOAC Teaching Note (2000) includes safety zones and neutralized zones among the areas specially protected by IHL. It states that these zones are established by agreement and may not be attacked. 
France, Fiche didactique relative au droit des conflits armés, Directive of the Ministry of Defence, 4 January 2000, annexed to the Directive No. 147 of the Ministry of Defence of 4 January 2000, p. 5.
France’s LOAC Manual (2001) notes that the laws of armed conflict afford a special protection to certain areas, among which are safety zones and neutralized zones. It states that safety zones are established by agreement between the belligerents in order to shelter wounded, sick, disabled or aged persons, children, expectant mothers and mothers of children under the age of seven; neutralized zones are set up by written agreement between the belligerents with the aim of sheltering the wounded and sick, as well as the civilian population located therein. The manual prohibits attacks against both types of zones. 
France, Manuel de droit des conflits armés, Ministère de la Défense, Direction des Affaires Juridiques, Sous-Direction du droit international humanitaire et du droit européen, Bureau du droit des conflits armés, 2001, pp. 125–126.
France’s Penal Code (1992), as amended in 2010, states in its section on war crimes common to both international and non-international armed conflicts:
Intentionally launching attacks against … hospitals and places where the wounded and sick are collected, provided that they are not used for military purposes, is punishable by 20 years’ imprisonment. 
France, Penal Code, 1992, as amended in 2010, Article 461-13.
According to the Report on the Practice of France, France has consistently upheld the general principle of protection of safety zones, the principle implying that it is prohibited to launch attacks or bombardments against these zones. The report notes that France was the initiator of the concept of safety zones. 
Report on the Practice of France, 1998, Chapter 1.8.