People queue for gasoline following a massive earthquake and tsunami at a gas station in Palu, Central Sulawesi, Indonesia, Monday, Oct. 1, 2018. A mass burial of earthquake and tsunami victims was being prepared in a hard-hit city Monday as the need for heavy equipment to dig for survivors of the disaster that struck a central Indonesian island three days ago grows desperate. (AP Photo/Tatan Syuflana)

Jakarta - Indonesia has accepted emergency foreign aid from 18 countries after two earthquakes and a tsunami devastated Sulawesi island last week, leaving hundreds dead and thousands displaced.

Hopes of finding survivors in the rubble grew slim as the death toll from Friday's 5.9- and 7.4-magnitude earthquakes and subsequent tsunami hovered at 844, the National Disaster Management Agency said. Officials warned that the figure was likely to increase.

Major aid group Aksi Cepat Tanggap said at least 1,203 bodies had been recovered, but disaster agency spokesman Sutopo Nugroho cautioned that the estimate was not official.

At least 90 people were unaccounted for, and another 48,000 have been displaced, Sutopo said. 

President Joko Widodo agreed to accept international aid after 18 countries - including the United States, Japan, Saudi Arabia and Qatar - offered help as a gesture of solidarity, security minister Wiranto said.

The European Union said it released an initial 1.5 million euros (1.7 million dollars) in emergency humanitarian assistance, while the United States said it stood "ready to assist in the relief effort."

Nugroho Budi Wiryanto, operations chief for the National Disaster Search and Rescue Agency, said a lack of heavy equipment and fuel was "making it hard for us to recover victims."

Sutopo said aid supplies had began arriving in Palu and were being distributed to those in need. 

Heavy machinery was also on the way from other areas on Sulawesi. 

Search and rescue workers were beginning to reach the districts of Donggala and Sigi, which were largely isolated due to landslides, damaged roads and other infrastructure.

Hopes of finding survivors were fading in many areas. Several paragliding athletes, including two South Korean nationals, were feared to be beneath the rubble of a collapsed seven-storey hotel in Palu, the capital of Central Sulawesi province, local media reported. 

Khalid, a rescue worker, told local television that no more voices were heard from the hotel rubble after a woman was rescued. 

"On the first day we heard voices from nine people. Yesterday there were voices from only two people," he said. 

Elsewhere in Palu, workers continued to search for survivors from a collapsed shopping mall.

Armed forced commander Air Chief Marshal Hadi Tjahjanto said the dead would be buried in a 1,000-square-metre mass grave.

"We'll bury them as soon as possible. Let's hope that it will be done in one or two days," he said. 

Some residents in Palu complained about the lack of aid.

"No one has come here to help," Mahmud, an elderly resident of Balaroa village, told Metro TV. "No one has given us assistance, not even a glass of water!" 

"I could not save my wife. I picked up her body myself," Mahmud said.

Amir Sidiq, another Balaroa resident, told Metro TV how the earth moved violently and upended houses 20 metres from their original positions. He appealed for help in recovering the bodies buried in collapsed houses.

"No one from the government or any organization has come to organize the recovery of dead bodies, only us, the local people," he said. "I guarantee that in one or two days, this place will smell of dead bodies." 

Indonesia sits on the Pacific Ring of Fire, an area known for seismic upheavals and volcanic eruptions. The Sulawesi quakes came after more than 550 people were killed and more than 400,000 were displaced in August in a series of powerful quakes that devastated the Indonesian resort island of Lombok.

About 230,000 people in a dozen countries died after a magnitude-9.1 earthquake off the west coast of Indonesia's Sumatra island spawned a devastating tsunami on December 26, 2004.