The 7.5 magnitude undersea quake struck early on Monday, killing at least six people and injuring more than 150.
Two more bodies were pulled from the rubble on Tuesday, adding to the four already reported dead.
Local officials say more than a thousand buildings were damaged across two provinces, forcing many people out of their homes.
The shallow quake struck in the middle of the night off the coastal town of Gorontalo. Authorities immediately warned it was strong enough to cause a tsunami but no wave materialised.
- Australian Broadcasting Corporation
- © ABC