manila pro-islamic state militants kill six soldier wound four others southern philippine island military spokesman say friday army focus remain rebel group regain control marawi city army shift operations basilan island end five-month combat operations marawi last month kill militants top leaders include isnilon hapilon emir pro-islamic state group southeast asia go abu sayyaf elements continue exist basilan time skirmish report us specifically morning military spokesman major-general restituto padilla tell news channel anc ten soldier wound six die way medical facility wednesday even troop search abu sayyaf sub-commander furiji indama clash militant group sumisip town add militants abu sayyaf notorious bomb behead extortion kidnap-for-ransom south mainly roman catholic philippines take part attack marawi may lead bloody five-month battle two army battalions send reinforce soldier take heavy gunfire well-entrenched militants spokeswoman captain jo-ann petinglay tell reporters add two attack helicopters also provide close air support undetermined number militants kill wound four-hour battle petinglay say continue chase abu sayyaf finish add presence pro-islamic state militants among top internal security threats philippines marawi siege raise alarm southern philippines fast become asian hub ultra-radical group islamist militants kill six soldier southern philippines