He warned that the death toll could be much higher than what has been reported, possibly in the thousands.
Eleven deaths had been recorded in the region of Donggala to the north of Palu, it said.
The death toll in the devastating quake and tsunami that hit Indonesia's island of Sulawesi increased to 832 on Sunday as rescue workers combed through concrete and lumber searching for survivors, the country's disaster management agency said.
"People were still going about their activities on the beach and did not immediately run", said Sutopo Purwo Nugroho, spokesman for Indonesia's National Disaster Management Agency, adding that the death toll would "continue to rise as the search continues". Hundreds were badly injured and at least 17,000 people were left homeless, Nugroho said. Officials had estimated about 50 people could be inside.
The number of casualties was no doubt increased by the fact that hundreds of people had descended on Palu's beach for a festival to celebrate the city's anniversary, due to start Friday night.
Dozens of injured people were being treated in tents set up in the open.
An AP reporter saw bodies partially covered by tarpaulins and a man carrying a dead child through the wreckage.
The tsunami was triggered by a strong quake that brought down buildings and sent locals fleeing for higher ground as a churning wall of water crashed into Palu, where there were widespread power blackouts.
Dramatic video footage captured from the top floor of a parking ramp in Palu, almost 80 kilometers from the quake's epicentre, showed waves bring down several buildings and inundate a large mosque.
A 7.5-magnitude quake triggered a massive tsunami on Friday evening, which crashed into Palu, Donggala and the surrounding settlements.
It comes after natural disasters in July and August killed nearby 500 people on the holiday island of Lombok, southwest of Sulawesi.
BNPB said in news briefing in Jakarta.
Television pictures showed scores of residents shouting, "We're hungry, we need food" as soldiers distributed rations from a truck in one neighbourhood, while footage from elsewhere showed people making off with clothes and other items from a wrecked mall.
"We have heard nothing from Donggala and this is extremely worrying".
Many people return day after day to undertake the grim task of looking through the bodies.
"Humanitarian groups are struggling to get people into affected areas", she said.
AirNav said one of its air traffic controllers, aged 21, died in the quake after staying in the tower to ensure a flight he had just cleared for departure got airborne safely. Such shallow quakes tend to be more destructive.
The twin disasters - a 7.5-magnitude quake, and the swirling wall of water it unleashed - killed at least 405 people in Palu and destroyed thousands of buildings there, including a shopping mall, a hotel, seaside restaurants and several mosques.
In the nearby city of Donggala, home to almost 300,000 people, a large bridge with yellow arches that spanned a coastal river collapsed.
Thousands of homes, hotels, shopping centers, hospitals and other public facilities were damaged, Nugroho said.
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.
Friday's tremor was also felt in the far south of the island in its largest city Makassar and on neighboring Kalimantan, Indonesia's portion of Borneo island.
The initial quake struck as evening prayers were about to begin in the world's biggest Muslim majority country on the holiest day of the week.
Many have spent the last days desperately searching for loved ones while dealing with the trauma of the disaster.