The massive 7.5-magnitude tremor struck Friday and sent monster waves barrelling into the island of Sulawesi, leaving at least 844 dead in the seaside city of Palu and surrounding areas.
Authorities fear that the official death toll could be in thousands. The three areas have a combined population of about 1.4 million.
The desperation was evident across Palu, a city of more than 380,000 people that was struck by both the quake and the tsunami, its force apparently magnified in the surrounding inlet.
Mass burials have begun on Sulawesi for the victims recovered so far - almost all of them found in the city of Palu.
Many people grabbed diapers while one man clutched a rice cooker as he headed for the door. A woman was pulled still alive from a collapsed hotel in Palu and taken to hospital to recover, while 34 schoolchildren were found dead in a church that had been hit by a landslide.
More than 65,000 homes were damaged and more than 60,000 people have been displaced and are in need of emergency help, while thousands have been streaming out of stricken areas.
Some 1,200 Indonesian convicts escaped from three different detention facilities in the devastated region of Sulawesi following an quake and tsunami disaster, a justice ministry official said on Monday.
Video showed some of them screaming in anger because they were not able to get on a departing military plane.
According to National Disaster Mitigation Agency spokesman Sutopo Purwo Nugroho, the 7.5-magnitude quake resulted in "soil liquefaction", a phenomenon in which severe shaking from a powerful natural disaster can turn earth into mud.
He called for a "day and night effort" in response to the 7.5-magnitude quake - but landslides and damaged bridges are making access to some areas hard.
Before and after satellite images have also been released showing the scale of the devastation.
Damaged infrastructure is also making it hard for Indonesian troops to get emergency food, water and medical supplies to the victims.
A 100-metre wide mass grave in the town has already been filled with more than 500 bodies. The disaster devastated swathes of the eastern side of the island of Sulawesi.
Jakarta Post correspondent Andi Hajramurni says, "I ran into a mother and her child at the airport who asked me to share some of my water with her child".