Given the task definition and input, reply with output. From the given sentence, extract the phrase (often noun or verb) that carries the given relationship. The generated phrase should be present in the sentence.

Given Relationship: 'be island in', Sentence: 'Travellers are advised to avoid travelling to most of Mindanao , an island in the southern Philippines , especially the Zamboanga peninsula and the Sulu archipelago , where ethnic and religious animosities fuel ongoing violence .'
island