There are fears thousands may have been killed by an earthquake and tsunami in Indonesia after the disaster's death toll rose to 832.

The country's disaster mitigation agency warned the figure could climb higher as the affected area on the Indonesian island of Sulawesi is bigger than initially thought.

Many people were reported trapped in the rubble of buildings brought down in the 7.5 magnitude earthquake which struck on Friday and triggered tsunami waves as high as six metres (20 feet).

Almost all the deaths have been recorded in the coastal city of Palu, where a mass burial will be held.

Image: Many have been left homeless by the disaster

"The [death toll] is believed to be still increasing since many bodies were still under the wreckage while many have not able to be reached," agency spokesman Sutopo Purwo Nugroho said.


He added that access to towns of Donggala, Sigi and Boutong is limited and there are no comprehensive reports from those areas.

It comes after Indonesian vice president Jusuf Kalla warned that "thousands" may have died in the disaster.

Image: An aerial view of Palu, which was struck by the tsunami

Image: Hospitals have been overwhelmed with patients and many are being treated outside

Hundreds of stricken people have been looting supermarkets and petrol stations amid a shortage of water, food and fuel.

Risa Kusuma, a 35-year-old mother comforting her feverish baby boy at an evacuation centre in Palu, said: "Every minute an ambulance brings in bodies.

"Clean water is scarce. The mini-markets are looted everywhere."

Image: People wear masks as they attempt to identify the bodies of their relatives

Image: A coastal bridge in Palu ripped apart by the tsunami

Residents were seen scrambling over broken glass and through broken-down barricades at a supermarket in Palu, before making off with plastic bin bags full of goods including nappies, crisps and gas canisters.

One man shouted: "There has been no aid, we need to eat.

"We don't have any other choice, we must get food."

Aid and supplies are being sent to badly-affected areas in military and commercial aircraft.

Image: The tsunami left a trail of destruction in Palu

Rescuers have been trying to reach trapped victims in collapsed buildings after the tsunami swept away buildings with massive waves.

People could be heard calling out from the eight-story Roa-Roa Hotel which toppled in the disaster.

"We managed to pull out a woman alive from the Hotel Roa-Roa last night," said Muhammad Syaugi, head of the national search and rescue agency. "We even heard people calling for help there yesterday."

Image: Search and rescue workers help rescue a person trapped in rubble following the disaster

Palu resident Nur Indah said: "The ground rose up like a spine and suddenly fell.

"Many people were trapped and buried under collapsed houses. I could do nothing to help.

"In the evening, some of them turned on their cellphones just to give a sign that they were there.

"But the lights were off later and the next day."

Image: Thousands are feared dead after the disaster

A Facebook page was created by worried relatives who posted pictures of missing family members in the hope of finding them alive.

The disaster agency said around 61 foreigners were in Palu when the quake struck, with most accounted for and safe.

Three French nationals, a Malaysian and a South Korean are missing, however.

Indonesian president Joko Widodo visited the area on Sunday, saying rescuers were having difficulty reaching victims because they lacked heavy equipment.

He added: "There are many challenges.

"We have to do many things soon but conditions do not allow us to do so."

Hospitals have been overwhelmed by the influx of those injured, with many people being treated outside.