Saudi Arabia appears to be using US-supplied white phosphorous munitions in its war in Yemen, based on images and videos posted to social media, raising concerns among human rights groups that the highly incendiary material could be used against civilians.
Under American regulations, white phosphorous sold to other countries is to be used only for signaling to other troops and creating smoke screens. When the munition explodes, it releaseswhite phosphorous that automatically ignites in the air and creates a thick white smoke. When used against soldiers or civilians, it can maim and kill by burning to the bone.
It is unclear exactly how the Saudis are using the munitions, but the government has already received widespread condemnation for its indiscriminate bombing in civilian areas since its campaign against rebel forces in Yemen began in 2015.