Jakarta - Nine people were killed and 11 were missing after a boat carrying 36 undocumented migrants from Afghanistan sank off Indonesia's Sumatra island, police said Friday.

Sixteen people were rescued by fishermen after the boat capsized Thursday off Riau province, said Arifin, a local police officer who like many Indonesians uses only one name.

Indonesia's Immigration Department has said about 900 asylum seekers from Afghanistan, Iraq, Sri Lanka and other countries are currently being detained pending an examination of their status.

Undocumented migrants from South Asia and the Middle East seeking better lives in Australia have for years used Indonesia as a transit country. (dpa)