PALU, Indonesia (AP) -- Rescue officials feared the full scale of Indonesia's earthquake and tsunami could climb far past the more than 800 already confirmed dead, as several large coastal towns remained cut off Sunday by damaged roads and downed communication lines.
The country's disaster agency said the death toll more than doubled to 832, and nearly all of those were from the hard-hit city of Palu on the island of Sulawesi. The regencies of Donggala, Sigi and Parigi Moutong -- with a combined population of 1.2 million -- had yet to be fully assessed.
"The death toll is believed to be still increasing since many bodies were still under the wreckage, while many have not been reached," said disaster agency spokesman Sutopo Purwo Nugroho. He said a mass burial would be held Sunday for health reasons.
Bodies covered in blue and yellow tarps lined the streets of Palu, while rescuers dug through rubble in the hopes of finding survivors from the twin disasters that struck Friday evening. There was particular focus on the eight-story Roa-Roa Hotel, where voices from underneath the rubble could be heard calling out for help on Saturday.
The cries from beneath the hotel, which appeared to have toppled over with its walls splintered like pickup sticks, had gone silent by Sunday afternoon. Officials had estimated some 50 people could be inside.
"We are trying our best. Time is so important here to save people," said Muhammad Syaugi, head of the national search and rescue team. "Heavy equipment is on the way."
Metro TV showed about a dozen rescuers in orange jumpsuits climbing over debris with a stretcher carrying the body of a victim from the modest business hotel.
Other rescuers were working to free a 15-year-old girl trapped under concrete in her house in Palu after it collapsed on her family during the magnitude 7.5 earthquake that spawned a tsunami.
Unable to move her legs under the heavy concrete rubble, Nurul Istikharah was trapped beside her dead mother and niece. Rescuers struggled to control water from a leaking pipe, fearing the girl may drown.
Istikharah was unconscious during part of the effort to free her, but rescuers continued to talk to her to try to keep her awake. Others offered her food and water.
Aid and supplies were being sent to the area via military and commercial aircraft, including helicopters, to reach badly affected areas. Officials said the area was lacking medical supplies, fuel, fresh water and experts.
Indonesian President Joko "Jokowi" Widodo toured Palu on Sunday.
"There are many challenges," Jokowi said. "We have to do many things soon, but conditions do not allow us to do so."
He said rescuers were having difficulty recovering victims because of a shortage of heavy equipment. He said authorities were deploying more heavy machinery that he hoped would arrive Sunday night so emergency workers can help recover more victims on Monday.
It's the latest natural disaster to hit Indonesia, which is frequently struck by earthquakes, volcanic eruptions and tsunamis because of its location on the "Ring of Fire," an arc of volcanoes and fault lines in the Pacific Basin. In December 2004, a massive magnitude 9.1 earthquake off Sumatra island in western Indonesia triggered a tsunami that killed 230,000 people in a dozen countries. Last month, a powerful quake on the island of Lombok killed 505 people.
In Donggala, the site closest to the earthquake's epicenter, aerial footage aired on Metro TV showed the sugary blond sands of beaches swept out to sea, as were some buildings. Damage to some buildings in the town was severe, with plywood walls shredded and chunks of concrete scattered on the pavement. Much of the damage, however, appeared limited to the waterfront.
Palu, which has more than 380,000 people, was strewn with debris from the earthquake and tsunami. A mosque heavily damaged by the quake was half submerged and a shopping mall was reduced to a crumpled hulk. A large bridge with yellow arches had collapsed.
The city is built around a narrow bay that apparently magnified the force of the tsunami waters as they raced into the tight inlet. Nugroho, the disaster agency spokesman, said waves were reported as high as 6 meters (20 feet) in some places.
Looters were stealing from the badly damaged shopping mall. They did not appear to be concerned about their safety, despite ongoing aftershocks and the structure's questionable stability.
In one devastated area in Palu, residents said dozens of people could still be buried under homes that collapsed.
"The ground rose up like a spine and suddenly fell," resident Nur Indah said while crying. "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."
Hundreds of people were injured and hospitals, damaged by the earthquake, were overwhelmed.
Nugroho said 61 foreigners were in Palu at the time of the disaster. Most of them had been accounted for, but one South Korean was believed to be trapped in the ruins of the Roa-Roa Hotel, while three others from France and one from Malaysia were missing. The survivors were to be evacuated to the Sulawesi city of Makassar in the island's far south.
Communications with the area were difficult because power and telecommunications were cut, hampering search and rescue efforts. Most people have slept outdoors, fearing strong aftershocks.
Indonesia is a vast archipelago of more than 17,000 islands that span a distance that would stretch from New York to London. It is home to 260 million people. Roads and infrastructure are poor in many areas, making access difficult in the best of conditions.
The disaster agency has said that essential aircraft can land at Palu's airport, though AirNav, which oversees aircraft navigation, said the runway was cracked and the control tower damaged.
Sulawesi has a history of religious tensions between Muslims and Christians, with violent riots erupting in the town of Poso, not far from Palu, two decades ago. Indonesia is the world's most populous Muslim country.