a group of islands belonging to Indonesia and located in the South China Sea, south of the Malay Peninsula. Area, approximately 3,400 sq km, excluding the Lingga Archipelago. The main islands are Bintan (1,075 sq km) and Batam. The islands are composed primarily of granites. The terrain is hilly, with elevations reaching 360 m. There are coral reefs along the shores. Pepper, rubber, and copra are harvested. There is a large bauxite deposit on Bintan. The inhabitants also engage in fishing. The chief port is Tandjungpinang.