Sulawesi's latest disaster happened as search teams continue to recover bodies from buildings flattened by Friday's 7.5-magnitude quake and tsunami waves up to 20ft high.
Two volcanic earthquakes were detected as Mount Soputan spewed a massive column of ash and smoke more than 20,00ft into the air during Wednesday's eruptions.
People living within a 2.5-mile radius of the peak were told to flee amid fears that villages could be hit by lava and falling volcanic ash.
The threat level was raised to "standby", meaning people living close to the volcano should move back and carry masks with them in case of falling ash.
Residents were also warned of post-eruption lava flows which can be carried away by rivers.