The initial quake had a magnitude of 6.2.
Since then, at least 26 aftershocks have been measured.
Pål Mårtensson was in Mamuju near the epicenter of the earthquake in Sulawesi when he was awakened by the quake at two o'clock at night.
- It was an incredibly strong earthquake.
Things around me overturned.
- Everyone immediately started going up to higher altitudes, because you were afraid of a tsunami.
Then we spent the whole night up there, says Pål Mårtensson.
Authorities warn of more earthquakes
Pål is now safe in a tent camp while Indonesian authorities warn that more aftershocks may occur.
At least 600 people have been injured and 15,000 have been evacuated from their homes.
Hear Swedish Pål Mårtensson talk about his experience in the player.