As the government in residence, the Taliban define what is and is not lawful. As was recently pointed out, the Nuremberg Laws were also legal.
[AnNahar] Taliban...Arabic for
students...
forces unlawfully killed 13 ethnic Hazara
...a grouping of Dari-speaking people of Sino-Tibetan descent inhabiting Afghanistan and Pakistain. They are predominantly Shia Moslems and not particularly warlike, which makes them favored targets...s, most of them Afghan soldiers who had surrendered to the murderous Moslems, a prominent rights group said Tuesday.