Kammala wannan jumlar: An kafa Hamas a hukumance ba da daɗewa ba, a ranar 14 ga Disamba, 1987, ta kafa wasu cibiyoyi masu kama da "al-Mujahidun al-Filastiniun", kamar su Abdullah Azzam Brigades. A tsakiyar 1991, a lokacin da
Farkon Intifada na Palasdinawa (1987-1994), an kafa Brigades na Izz ad-Din al-Qassam don samarwa Hamas da karfin soja, daga baya aka san shi da reshen Hamas.