Indonesia Thursday called off the grim search for those killed in a quake-tsunami, with no hope of retrieving around 5,000 bodies believed to be still buried under the ruins nearly two weeks after the disaster.

The magnitude 7.5 quake and a subsequent tsunami razed swathes of the city of Palu on Sulawesi island on September 28.

A total 2,073 bodies had been recovered since the twin disasters, authorities said Thursday.

But there are fears that 5,000 more could be buried beneath the ruined city, where entire villages were swallowed.

Rescuers had struggled to find remains in the twisted wreckage, a job made worse as mud hardened and bodies decomposed in the tropical heat.

"The search and rescue (SAR) operation for the victims will end this Thursday afternoon," SAR field director in Palu, Bambang Suryo, told AFP.

"Considering the difficulty on the ground, we really need to consider the health and safety of our rescue personnel."

Teams would however remain on standby in Palu to assist where needed until October 26, when a state of emergency is expected to be lifted.

The government earlier indicated that hard-hit areas would be left untouched as mass graves.

Prayers were expected in coming days at three of the worst-hit areas -- Balaroa, Petobo and Jono Oge.

- 'It will rise again' -

Parks and monuments are also eventually planned at these locations to remember the untold thousands of dead who will never be found.

Those zones were all but destroyed by liquefaction, a phenomenon where the brute force of a quake turns soil to quicksand.

At Balaroa, 29-year-old Muhammad Rasidi was coming to terms with the fact his three missing siblings would never be found.

"What else can we do? We just have to accept it," he told AFP.

More than 200,000 people remain in dire need of humanitarian assistance in Palu.

Clean drinking water and medical supplies are still in short supply, and many survivors were entirely reliant on handouts to get by.

"What's important is that we get support from the government", said Sapri, who lost 10 members of his family at Balaroa. Many Indonesians go by one name.

Central Sulawesi governor Longki Djanggola said although the search effort was over, survivors would be supported in their time of need.

"I am sure Central Sulawesi will rise again," he said.

The United Nations has sought $50.5 million for immediate relief to help the victims.

Planeloads of donations have flown into Palu from the United States, Australia, the European Union and the Philippines, among many others.

Nearly 90,000 people were displaced by the disaster, many sheltering in tents outside their destroyed homes.

United Nations Secretary General Antonio Guterres will tour the disaster zone with Indonesian Vice President Jusuf Kalla on Friday.

- Aid challenges -

Humanitarian efforts have accelerated into the disaster-ravaged city, but the recovery effort was criticized for moving too slowly.

Looters ransacked shops in the immediate aftermath of the disaster, as food and water ran dry and convoys bringing life-saving relief were slow to arrive.

Getting vital supplies to the affected areas proved hugely challenging as flights into Palu were limited by its small airport, leaving aid workers facing grueling overland journeys.

Indonesia initially refused international help, saying the military had the situation in hand.

Four days after the disaster, once the picture became clearer, President Joko Widodo reluctantly agreed to allow in overseas aid.

But earlier this week foreign aid workers were told to withdraw their personnel, frustrating some groups keen to help out on the ground.

Some foreign rescue teams were unable to access the disaster zone and deploy quickly to help search for the dead and missing.

"We just came here because the government of Indonesia asked for assistance," said Marcus Butler from South African charity Gift of the Givers, which was denied permission to help with the search.

"They say there is no need for aid in Indonesia. But look at all these people," he told AFP.

Indonesia sits along the world's most tectonically active region, and its 260 million people are vulnerable to earthquakes, tsunamis and volcanic eruptions.

Another earthquake rattled the region Thursday, killing at least three people in Java and sending tourists and IMF delegates in Bali for a major summit scrambling from hotels.

The 6.0-magnitude earthquake struck off the coast of Bali and Java islands in the early hours, jolting residents awake and sending them rushing into the streets.

A string of earthquakes in Lombok, in eastern Indonesia, killed more than 550 people over the summer.