The number of confirmed deaths stood at 844 on Tuesday
Officials fear the death toll will rise into the thousands. Indonesia has said it would accept offers of international aid, having shunned outside help earlier this year when an earthquake struck the island of Lombok.
The number of confirmed deaths stood at 844 on Tuesday, most of them in Palu, the main city in the disaster zone, where rescuers were hunting for victims in the ruins.
“We suspect there are still some survivors trapped inside,” the head of on rescue team, Agus Haryono, told Reuters at the collapsed seven-storey Hotel Roa Roa.
About 50 people were believed to have been trapped when the hotel was brought down by the 7.5 magnitude earthquake on Friday.
The quake triggered tsunami waves as high as six metres (20 feet) that smashed into the city’s beachfront, about 2km from the hotel. About 12 people have been recovered from the ruins of the hotel, three of them alive.
Haryono pored over the hotel’s blueprints and building plans, searching for possible pockets and a way through to them. A faint smell of decomposition hung in the air.
“We have to be very careful so we don’t risk hurting any survivors when we move the debris,” he said.
Power has yet to be restored in the area and access by land to outlying villages has been disrupted by broken roads, landslides and downed bridges.
Aftershocks have rattled jangled nerves.
A 5.9 magnitude quake struck earlier on Tuesday near the southern island of Flores, hundreds of kilometres from Sulawesi, the U.S. Geological Survey said. There no immediate reports of casualties or damage.
A particular horror in several areas in and around Palu was liquefaction, which happens when soil shaken by an earthquake behaves like a liquid.
About 1,700 houses in one Palu neighbourhood were swallowed up, with hundreds of people believed buried, the national disaster agency said.
There was also mounting concern over Donggala, a region of 300,000 people north of Palu and close to the epicentre, and two other districts - with a combined population of about 1.4 million.
Initial reports from Red Cross rescuers who had reached the outskirts of Donggala district were chilling.
“The situation in the affected areas is nightmarish,” Jan Gelfand, head of an the International Federation of Red Cross and Red Crescent Societies (IFRC) office in Jakarta said in a statement.
“The city of Palu has been devastated and first reports out of Donggala indicate that it has also been hit extremely hard by the double disaster,” Gelfand said.
Nearly 60,000 people have been displaced and are in need of emergency help, while thousands have been streaming out of the stricken areas.
Chief security minister Wiranto said on Monday the government was trying to meet survivors’ immediate needs and would accept offers of international help.
“Right now, we need emergency aid,” Wiranto said, referring to the foreign aid that would be airlifted to Palu, 1,500km (930 miles) northeast of Jakarta.
Commercial airlines have struggled to restore operations at Palu’s quake-damaged airport, but military aircraft took survivors out on Monday.
About 3,000 people thronged the airport hoping to get on any flight and officers struggled to keep order.
Wiranto said a navy vessel capable of taking 1,000 people at a time would also be deployed to help with the evacuation.
He said the power utility was also working to restore electricity: “Without energy, everything is crippled.”
Anger and desperation among traumatized residents of Palu appeared to be simmering, with some outbreaks of looting.
“Stop hiding Mr Mayor,” was daubed on a wall in one part of Palu. Mayor Hidayat was unavailable for comment.