What happened
Al-Aqsa Martyrs Brigades emerged from within Fatah's own structures during the Second Intifada, drawing members and, per Israeli and some Palestinian accounts, funding and weapons through networks connected to Fatah's security and political apparatus, distinguishing it from Hamas and Islamic Jihad, which were entirely separate organisations with their own independent leadership and financing (largely from Iran, in Islamic Jihad's case). Arafat's precise degree of operational knowledge or control over specific Brigades attacks remains disputed — his government never publicly disavowed the group with the clarity that would have signalled a genuine break, and some captured internal PA financial documents, cited by Israeli and some international investigators, suggested funds had flowed toward individuals later linked to Brigades cells, though the full extent of any direct command relationship was never conclusively established in a manner both Israeli and independent investigators agreed on.
HRW's 2002 report, 'Erased in a Moment,' treated attacks by Fatah-linked, Hamas, and Islamic Jihad groups as sharing a common legal character: deliberate targeting of civilians in buses, restaurants, and other public spaces, regardless of which faction claimed responsibility, meeting the definition of war crimes and — given their systematic nature over a sustained campaign — potentially crimes against humanity. This is why the entry is placed in Arafat's own file rather than solely in Hamas's: whatever the precise chain of command, these were attacks carried out under the banner of the same national movement Arafat led, by a group that never faced meaningful internal PA consequences for its campaign against Israeli civilians during his lifetime.