Indonesia on Tuesday told foreign aid workers that their help was not needed in disaster-ravaged Palu and they should go home, frustrating relief efforts after a quake-tsunami killed more than 2,000 people.

Foreign teams on the ground were told new rules barred them from searching for the dead in hard-hit parts of Palu, where thousands are missing since the Sept 28 twin disaster.

Indonesia initially refused international help but President Joko Widodo reluctantly agreed to allow in overseas aid once the picture became clearer on Sulawesi island.

Foreign aid poured into the ravaged city of Palu where authorities believe 5,000 people could be missing and 200,000 survivors desperately need food, water and other life-saving supplies.

But international search and rescue teams were prevented on Tuesday from accessing hard-hit parts of Palu, where thousands are believed to be buried underneath rubble.

Ahmed Bham from South African charity, Gift of the Givers, was told that new rules barred foreign urban search and rescue teams (USAR) from playing any part in retrieving the dead.

They were told, "all foreign USAR teams should make their way obviously back to their countries. They don't need them in Indonesia", he said.

"We've got experienced search and rescue teams here in Indonesia with really specialised equipment. I'd like to use them," he told AFP in Palu.

Their 27-strong team arrived in Palu three days ago from Johannesburg, but days of delay frustrated their wish to join the search for the dead.

"A lot of days were wasted where we could have assisted and used our expertise and skill," Bham said.

"There seemed to be — I won't say red-tape — but it was just like, 'you can't work here, you can't do this, you can't do that'. It's something we haven't experienced in other major disasters like this."

'They can't work'

Indonesia's disaster agency issued a set of rules over the weekend instructing international staff to leave Palu and requiring foreign donations be channelled through local partners.

"The truth is that they have put out a statement saying foreign personnel should be withdrawn," World Vision Australia Chief Advocate, Tim Costello, told Australian broadcaster ABC on Tuesday.

"It is very odd as foreign journalists are free to walk around and report. This is what's very strange."

He said aid was reaching survivors but, "it is still, for us who are used to these crises, too slow".

Bham said most of the international teams he had seen in Palu were at the airport.

"They can't work. They are starting to make their way back to their countries," he said.

Disaster agency spokesman Sutopo Purwo Nugroho said no foreign aid workers had been asked to leave Palu yet.

"But in Lombok, there were many (asked to leave)," he told reporters on Tuesday.

A string of earthquakes in Lombok in eastern Indonesia over the summer killed more than 550 people, sparking a major aid response.

"The president said we didn't need foreign aid anymore but they kept coming."

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

More than 70,000 people have been displaced since the 7.5-magnitude earthquake and subsequent tsunami tore through Palu.