Abu Sayyaf ( ; ; ' , ASG ; ) , unofficially known as the Islamic State of Iraq and the Levant – Philippines Province ' '' , is a Jihadist militant and pirate group that follows the Wahhabi doctrine of Sunni Islam . It is based in and around Jolo and Basilan islands in the southwestern part of the Philippines , where for more than four decades , Moro groups have been engaged in an insurgency seeking to make the province independent . The group is considered violent and was responsible for the Philippines ' worst terrorist attack , the bombing of Superferry 14 in 2004 , which killed 116 people . The name of the group is derived from the Arabic '' abu '' ( ) ( " father of " ) , and '' sayyaf '' ( ) ( " swordsmith " ) . As of 2012 , the group was estimated to have between 200 and 400 members , down from 1,250 in 2000 . They use mostly improvised explosive devices , mortars and automatic rifles
bombing of Superferry 14 in 2004
2004 SuperFerry 14 bombing
Abu Sayyaf