The tsunami, which was triggered by a volcano eruption, struck the Indonesian coast at 14:27 GMT on Saturday.
Rescue operation and evacuation are underway.
Indonesia is located in a seismically active zone known as the Ring of Fire and regularly suffers from powerful earthquakes.
On Monday, Indonesian President Joko Widodo warned that a new tsunami could hit the country, calling on the local authorities to do everything possible to prevent the emergence of new victims.