marawi city philippines philippine military say thursday big possibility top malaysian militant tip become islamic state point man southeast asia kill battle overnight twenty rebel among remain islamic state loyalists hole devastate heart marawi city kill late fight likely include malaysian mahmud ahmad say colonel romeo brawner deputy commander military task force big possibility dr mahmud among brawner tell reporters definite match probably dna sample maybe dental record confirm mahmud death would blow effort islamic state back foot syria iraq establish presence mindanao island history rebellion home predominantly roman catholic nation muslim minority marawi siege philippines big security crisis years experts see prelude ambitious bid militants exploit mindanao poverty use jungles mountains base train recruit launch attack region arm force statement say 13 militants kill overnight seven monday morning two hostages rescue information provide mean authorities increasingly become confident mahmud dead 39-year-old former university lecturer believe pivotal raise channel fund alliance foreign fighters occupation last 150 days kill 1,000 people mostly rebel central marawi flatten government air strike experts say mahmud could become islamic state southeast asian emir death monday isnilon hapilon head alliance seek carve islamic state wilaya southern philippines philippine soldier monday kill hapilon target u.s. federal bureau investigation also kill omarkhayam maute one two brothers helm maute militant clan mahmud see video alongside hapilon maute brothers plot marawi siege security experts say study pakistan learn make bomb al qaeda camp afghanistan leave malaysia 2014. brawner say military relentless finish rebel unsure many leave estimate monday 20 40 fighters resistance still fact hear background battle ongoing say security analyst rommel banlaoi say end mahmud would mean end extremists presence mindanao still high-value terrorist personalities still large mindanao mention foreign fighters come indonesia elsewhere arab world say television elusive mix communities time hang arm group mastery terrain mindanao difficult catch military philippines say 'big possibility malaysian militant leader kill