A speedboat carrying 48 people has capsized off Indonesia's part of Borneo island, killing at least eight passengers.

The accident happened Monday when the boat Anugrah Express was traveling from Tanjung Selor, the capital of North Kalimantan province, to Tarakan in the same province.

Manangap Djumala, a search and rescue official in Tarakan, says several other people were believed to be missing. Unconfirmed reports say 40 people have been rescued.

The boat's manifest says it was carrying 43 adults and five children.

Djumala says police are investigating the cause of the accident.

Boat accidents are common in Indonesia because of poorly enforced safety regulations in the world's largest archipelago nation, where ships are a popular and relatively cheap form of transportation.