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Malaysia
Practice Relating to Rule 7. The Principle of Distinction between Civilian Objects and Military Objectives
Section E. Attacks against civilian means of transportation
The Report on the Practice of Malaysia states that no civilian aircraft may be attacked. 
Report on the Practice of Malaysia, 1997, Answers to additional questions on Chapter 1.4.
In 2010, during the consideration of the Status of the 1977 Additional Protocols by the Sixth Committee of the UN General Assembly, a statement of the delegation of Malaysia was summarized by the Committee in its records as follows:
8. [The delegate of Malaysia] said that …
10. … [t]he laws of naval warfare incorporated the fundamental principles of international humanitarian law, including necessity and proportionality …
11. [In the case of the attacks by the Israel Defense Forces on the Mavi Marmara and five accompanying vessels in May 2010] … Clear justification needed to be provided for unprovoked attacks on neutral vessels. 
Malaysia, Statement by the delegation of Malaysia before the Sixth Committee of the UN General Assembly on the Status of the Protocols Additional to the Geneva Conventions of 1949 and relating to the protection of victims of armed conflict, 18 October 2010, as published in the summary record of the 13th meeting, 8 December 2010, UN Doc. A/C.6/65/SR.13, §§ 8, 10 and 11.