Two tourists are still missing.
Lutfi said the boat was skippered by a 13-year-old. Police will investigate whether negligence was a contributing factor.
Boat accidents are common in Indonesia, due to lax safety standards.
In January last year, 10 people went missing after a boat carrying 20 migrant workers to neighbouring Malaysia capsized off the coast of Sumatra island.
Last month, two fishing trawlers collided in West Java. Three people were found dead and 13 were still missing when the search ended.
Also last month, an Indonesian military submarine sank and broke apart, killing all 53 Navy personnel.