That looks more like White Phosphorus or illumination flares. Also I have never heard of cluster incendiary munitions.
It depends on the usage:
White phosphorus munitions can be used on battlefields to make smoke screens, generate illumination, mark targets or burn bunkers and buildings.
Because it has legal uses, white phosphorus is not banned as a chemical weapon under international conventions. But some U.S. military training manuals say its use against people is banned.
Under international law, white phosphorus is considered an incendiary weapon, defined by Protocol III of the Convention on the Prohibition of Use of Certain Conventional Weapons as “any weapon or munition which is primarily designed to set fire to objects or to cause burn injury to persons through the action of flame, heat or combination thereof, produced by a chemical reaction of a substance delivered on the target.”
The protocol prohibits using incendiary weapons against military targets located among civilians, although the United States has not signed it and is not bound by it. According to Human Rights Watch, “customary laws of war also prohibit the anti-personnel use of incendiary weapons so long as weapons less likely to cause unnecessary suffering are available.”
