Practice Relating to the Use of Prohibited Weapons
Ecuador’s Naval Manual (1989) provides: “The following acts constitute war crimes: … use of prohibited weapons or ammunition.” 
Ecuador, Aspectos Importantes del Derecho Internacional Marítimo que Deben Tener Presente los Comandantes de los Buques, Academia de Guerra Naval, 1989, § 6.2.5(10).
In its written statement submitted to the ICJ in the Nuclear Weapons case in 1995, Ecuador stated:
The use of nuclear weapons has the consequences that fit perfectly with the legal figure of war crimes against humankind: the assassination and extermination of entire populations and other inhuman acts committed against the civil population. 
Ecuador, Written statement submitted to the ICJ, Nuclear Weapons case, 20 June 1995, p. 2, § F.