IS is using the earthquake in southern Turkey and northern Syria as a cover to commit atrocities. With the world's attention on other matters, the group was able to undertake a terrible massacre of Syrian civilians. The fight against IS is definitely not over, and all parties involved must continue their effort in liquidating the group.
Though one may assume that an attack like this was obviously committed by IS, there is a possibility that the Fatemiyoun Brigade, an Iran-backed Afghan Shiite militia, actually is the real perpetrator. Iran's sectarian militias are known for their brutality and also have tactically tried to blend in with the local population in the past. Iran continues to meddle in the local politics of the Syrian desert, and one must keep in mind that it is Iran that benefits from chaos in Syria.