Most likely suspect: another and differing sect of Muslims.
Zealous and intensely jealous, the lives and collective property of Muslims are in greater danger from other Muslims than these would ever be from non-Muslims. Of all the mischief being carried out today, the vast preponderance is Muslim on non-Muslim, and Muslims on other Muslims. Non-Muslim on Muslim is of much less importance. A mere pinprick, if you would. (We have this last on good authority from no less than Jean-Francois Kerre`, who served in Viet Nam, you know.)
The recent conflict in Gaza pales into near insignificance compared to the depredations of the Islamic Caliphate on its immediate neighbors in Iraq, both in terms of number died and in property destruction.
Reports today say they've arrested a Jordanian. No word on the motive, but you probably nailed it.