Pretty much. AS for sure carried it out and received the material from their foreign backers. It's not a weak useless nation like Ethiopia either.
Personally I believe al kebab receives no foreign support, al kebabs ideology places these foreign governments as murtadeen, even arab ones, to take support from them is hypocritical. Instead I think they steal weapons from the incompetent bantu amisom officers who are always blind sided and ambushed.