A group calling itself the "Balata Brigade" warned Israelis against a planned visit to Joseph's Tomb near Nablus on Tuesday evening, stating "we are ready, and you will see the unthinkable."
The Balata Brigade first announced its establishment in mid-October.
The threat comes after IDF Judea and Samaria Division commander Brig.-Gen. Avi Bluth approved a visit by right-wing politicians to Joseph's Tomb, according to Haaretz.
The planned visit comes shortly after much of the Lion's Den terrorist group, which operated in the Nablus area, was killed or surrendered to Palestinian Authority security services.