Related Rule
Ecuador
Practice Relating to Rule 7. The Principle of Distinction between Civilian Objects and Military Objectives
Ecuador’s Naval Manual (1989) provides: “Only combatants and other military objectives may be attacked.” 
Ecuador, Aspectos Importantes del Derecho Internacional Marítimo que Deben Tener Presente los Comandantes de los Buques, Academia de Guerra Naval, 1989, § 8.1.1.
Ecuador’s Naval Manual (1989) states: “The wanton or deliberate destruction of areas of concentrated civilian habitation, including cities, towns, and villages, is prohibited.” 
Ecuador, Aspectos Importantes del Derecho Internacional Marítimo que Deben Tener Presente los Comandantes de los Buques, Academia de Guerra Naval, 1989, § 8.5.1.1.
Ecuador’s Naval Manual (1989) provides:
Civil passenger vessels at sea and civil airliners in flight are subject to capture but are exempt from destruction. Although enemy lines of communication are generally legitimate military targets in modern warfare, civilian passenger vessels at sea, and civil airliners in flight, are exempt from destruction, unless at the time of the encounter they are being utilized by the enemy for a military purpose (e.g., transporting troops or military cargo) or refuse to respond to the directions of the intercepting warship or military aircraft. Such passenger vessels in port and airliners on the ground are not protected from destruction. 
Ecuador, Aspectos Importantes del Derecho Internacional Marítimo que Deben Tener Presente los Comandantes de los Buques, Academia de Guerra Naval, 1989, § 8.2.3(6).