 A military intelligence report said the attack was staged by a "four-man urban terrorist group" of Abu Sayyaf, which has been linked to al-Qaeda.Philippine National Police chief Director General Hermogenes Ebdane Jr. stated the motorcycle driver had been identified as a member of Abu Sayyaf from a sketch based on witnesses' accounts and the body.According to police, the bomb that exploded in Malagutay weighed around a kilo and contained "brownish" explosive that may have been a mixture of gunpowder and TNT.