`` Revenge , '' references to `` redemption ( of ) Zion '' were on the mosque , seminary . `` There is no room for such deplorable activity in Jerusalem , '' Mayor Nir Barkat said Thursday . Both buildings were defaced with anti-Arab and anti-Christian slurs . The same day as this attack, a group calling itself Islamic State claimed responsibility for an assault at a Coptic church in Alexandria that left 21 people dead. A `` holy war '' is underway against Muslims , Christians .
`` Revenge , '' references to `` redemption ( of ) Zion '' were on the mosque , seminary . Both buildings were defaced with anti-Arab and anti-Christian slurs . The same day as this attack, a group calling itself Islamic State claimed responsibility for an assault at a Coptic church in Alexandria that left 21 people dead. A `` holy war '' is underway against Muslims , Christians .