(FOX NEWS) -- Three Americans were among four worshipers killed in a Jerusalem synagogue Tuesday by a pair of Palestinians wielding meat cleavers and a gun and shouting "Allahu Akbar" in a brutal attack that prompted a vow from Prime Minister Benjamin Netanyahu to "respond harshly."
The American citizens -- identified as Aryeh Kupinsky, Kalmen Levin and Moshe Twersky -- were killed along with a Briton when the assailants, identified as cousins, stormed the building and began attacking people. Police said those killed were all immigrants to Israel and held dual citizenship.
Eight others were injured -- one critically -- before the attackers were killed in a shootout with police. The Times of Israel cited witnesses who said the attackers stormed the synagogue, in the ultra-Orthodox Har Nof neighborhood in the western part of Jerusalem, shouting "Allahu Akbar," Arabic for "God is Great," and creating a horrific scene of bloody carnage.