Saudi Arabia appears to be using U.S.-supplied white phosphorus 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 U.S. regulations, white phosphorus sold to other countries is to be used only for signaling to other troops and creating smoke screens. When the munition explodes, it releases white phosphorus 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.

The only company with the rights to sell to the U.S. government the white phosphorus round pictured in the image is General Dynamics Ordnance Tactical Systems, according to Marine Corps Systems Command documents distributed in 2015. The shell’s design is owned by TDA-Armaments of France. Both TDA-Armaments and General Dynamics manufacture the munition, although it is unclear which country manufactured the round pictured.

When asked about the image, General Dynamics spokeswoman Laurie VonBrocklin said “it wouldn’t be appropriate for us to comment” and deferred further questions to the Pentagon and the State Department.

The shell’s color pattern is the most telling, as the greenish-hue interrupted by yellow bands and red writing is internationally recognized as indicating white phosphorus munitions.

Read More: Washington Post

Featured Image – A Saudi Instagram account showed a WP shell with the words “Martyr Jamil Hadi” written on it. – Instagram