Aru Islands or Aroe Islands (both: äˈrō) [key], group of about 95 low-lying islands, 3,306 sq mi (8,563 sq km), E Indonesia, in the Moluccas, in the Arafura Sea, SW of New Guinea. The largest island is Tanahbesar; Dobo, the chief port of the group, is on Wamar, just off Tanahbesar. Products include sago, coconuts, tobacco, mother-of-pearl, trepang, tortoiseshell, and bird of paradise plumes. The inhabitants are of a mixed Papuan and Malay stock. The islands were discovered by the Dutch, who colonized them after 1623. Arru is another spelling.