Fighting has erupted between Muslim rebels and Christians in Zamboanga City . At least 158 people have been killed , including many civilians . United States : `` We are increasingly alarmed by the situation and the growing needs of people caught up with violence , '' said Luiza Carvalho , U.N. resident and humanitarian coordinator in the Philippines . The unrest has displaced more than 100,000 people . Authorities believe about 100 hostages are still being held by rebels .
Fighting has erupted between Muslim rebels and Christians in Zamboanga City . At least 158 people have been killed , including many civilians . United States : The unrest has displaced more than 100,000 people . Authorities believe about 100 hostages are still being held by rebels .