When Syrian Government’s Armed Forces failed to break into eastern Ghout cities and towns, as well as Darayya, and Al Moadamyeh, they started to starve process and prevented the arrival of humanitarian relief
According to customary of IHL:
Rule 53. The use of starvation of the civilian population as a method of warfare is prohibited.
Rule 54. Attacking, destroying, removing or rendering useless objects indispensable to the survival of the civilian population is prohibited.
Rule 55. The parties to the conflict must allow and facilitate rapid and unimpeded passage of humanitarian relief for civilians in need, which is impartial in character and conducted without any adverse distinction, subject to their right of control.
Rule 56. The parties to the conflict must ensure the freedom of movement of authorized humanitarian relief personnel essential to the exercise of their functions. Only in case of imperative military necessity may their movements be temporarily restricted