Règle correspondante
Switzerland
Practice Relating to Rule 11. Indiscriminate Attacks
According to Switzerland’s Basic Military Manual (1987), the following constitutes a grave breach:
An attack which is launched without making any distinction [between civilians and civilian objects on the one hand and military objectives on the other hand] and which may affect the civilian population or civilian objects in the knowledge that the attack will cause loss of human life, injuries to civilians and damage to civilian objects which would be excessive in the sense of Article 57(2)(a)(iii) [of the 1977 Additional Protocol I]. 
Switzerland, Lois et coutumes de la guerre (Extrait et commentaire), Règlement 51.7/II f, Armée Suisse, 1987, Article 193(1)(b).
Switzerland’s Regulation on Legal Bases for Conduct during an Engagement (2005) states: “Indiscriminate attacks, i.e. attacks which cannot distinguish between protected persons/objects and military objectives, … are prohibited in any place and at any time.” 
Switzerland, Bases légales du comportement à l’engagement (BCE), Règlement 51.007/IVf, Swiss Army, issued based on Article 10 of the Ordinance for the Organization of the Federal Department for Defence, Civil Protection and Sports of 7 March 2003, entry into force on 1 July 2005, § 225.
In 2008, in its response to a question by a member of the National Council, Switzerland’s Federal Council wrote:
2. … Indiscriminate Qassam rocket launches against Israeli localities by irregulars and Palestinian groups are contrary to international law and must be condemned unequivocally. For that matter, in its press release of 29 February 2008, the FDFA [Federal Department of Foreign Affairs] clearly condemned the repeated rocket launches on Sderot and Ashkelon from the Gaza strip. 
Switzerland, National Council, Response by the Federal Council to Interpellation No. 08.3127, 14 May 2008, p. 1.
Switzerland’s ABC of International Humanitarian Law (2009) states:
Conduct of hostilities
Not all Means and methods of warfare are allowed in an Armed conflict. International humanitarian law stipulates the military operations, tactics and weapons that are permissible. The two generally accepted principles of Distinction and Proportionality are the basis for a number of specific rules such as the prohibition of direct attacks on the civilian population or on Civilian objects, the prohibition of indiscriminate attacks …
Distinction
… The principle of distinction imposes limits on means and methods of warfare: any Weapon or strategy that cannot be directed exclusively at a specific military objective is prohibited.
Means and methods of warfare
Even in war not everything is allowed. Various means and methods are prohibited, including … indiscriminate attacks, …
Terrorism
The concept of “terrorism” has not yet been defined in International law. International law, Human rights and international humanitarian law nonetheless do prohibit many terrorism related acts and activities.
In fact, according to international humanitarian law, acts generally considered as acts of terrorism, such as … indiscriminate attacks … are prohibited both in international and non-international armed conflict. 
Switzerland, Federal Department of Foreign Affairs, ABC of International Humanitarian Law, 2009, pp. 13–14, 17, 29 and 39.
In 2009, in response to a motion before the Council of States by the Commission on Foreign Policy, Switzerland’s Federal Council stated:
The humanitarian situation in Sri Lanka is of the highest concern to the Federal Council. It deplores the violations of international humanitarian law, in particular the undifferentiated and disproportional recourse to violence that has killed and wounded thousands of persons in the north of the country. 
Switzerland, Council of States, Response by the Federal Council to Motion No. 09.3358, 13 May 2009, p. 1.
In 2012, Switzerland’s Federal Department of Foreign Affairs issued a press release entitled “Appeal by the Swiss authorities for compliance with international humanitarian law in Syria”, which stated:
Deep concern about the humanitarian situation
2. Switzerland expresses its deep concern about the deterioration of the humanitarian situation in Syria. It deplores that because of non-compliance with international humanitarian law, in particular indiscriminate and disproportionate use of force, numerous civilian persons have already been killed.
International humanitarian law is applicable to non-international armed conflict.
4. International humanitarian law is applicable in non-international armed conflicts. All parties to the conflict are therefore obliged to respect its rules in all circumstances, including the rules protecting persons who are [not] or are no [longer] participating in the hostilities, as well as the rules relative to the means and methods of warfare. 
Switzerland, Federal Department of Foreign Affairs, “Appeal by the Swiss authorities for compliance with international humanitarian law in Syria”, Press Release, 15 November 2012.