Indonesia is in a race against time to save victims of a devastating earthquake and tsunami on Sulawesi island, the government said yesterday, as the official death toll rose to more than 1,300 and looting fuelled fears of lawlessness.

Four days after the double disaster struck, officials feared the toll could soar, as most of the confirmed dead had come from Palu, a small city 1,500 km (930 miles) northeast of Jakarta.

Some remote areas have been largely cut off after Friday's 7.5 magnitude quake triggered tsunami waves, destroying roads and bridges, and their losses have yet to be determined.

"The team is racing against time because it's already D+four," Sutopo Purwo Nugroho, spokesman of National Disaster Mitigation Agency, told a briefing in Jakarta, referring to four days since the quake.

He said rescuers had reached all four of the badly affected districts, which together have a population of 1.4 million, but he declined to give an estimate of casualties.

He gave few details of the conditions rescuers had found, saying they were similar to those in Palu.

Sand is placed over dead bodies of the victims during a mass burial at the Poboya Cemetery in Palu.

Earlier, President Joko Widodo called for reinforcements in the search for survivors saying everyone had to be found.

The official death toll surged to 1,347 with 800 people seriously injured.

There has been particular concern about Donggala, a district of 300,000 people north of Palu and close to the epicentre of the quake, which only a few aid workers have managed to reach.

Nugroho said it had been "devastated" by the tsunami.

In Palu, tsunami waves as high as six metres (20 feet) smashed into the beachfront, while hotels and shopping malls collapsed in ruins.

Before-and-after satellite pictures showed a largely built-up neighbourhood just south of Palu's airport seemingly wiped clean of all signs of life by liquefaction.

More than 65,000 homes were damaged and more than 60,000 people have been displaced and are in need of emergency help.

Photo: Reuters

The government has ordered that aid be airlifted in but there's little sign of help on Palu's shattered streets and survivors appeared increasingly desperate.

A Reuters news team saw a shop cleared by about 100 people, shouting, scrambling and fighting each other for items including clothes, toiletries, blankets and water.

Police were at the scene but did not intervene. The government has played down looting saying victims could take essentials and shops would be compensated.