MAMUJU, INDONESIA (AFP) - Rescuers scrambled to find buried survivors on Saturday (Jan 16) after a powerful earthquake on Indonesia's Sulawesi island killed dozens, injured hundreds and left more feared trapped in the rubble of collapsed buildings.

At least 46 people died after the 6.2-magnitude quake struck in the early hours of Friday, triggering panic among residents of the island, which was hit by a 2018 quake-tsunami disaster that killed thousands.

Search-and-rescue worked through the night as they pulled dozens of bodies from beneath crumpled buildings in Mamuju, a city of about 110,000 people in West Sulawesi province, where a hospital was flattened and a shopping mall lay in ruins.

Others were killed south of the city after the quake struck, as a strong aftershock jolted the area Saturday morning.

Grieving relatives began burying the dead at a local cemetery.

Planes and boats packed with food and other emergency supplies were arriving, with the navy reportedly sending a ship equipped with mobile medical services as Mamuju's still-standing hospitals were flooded with hundreds of injured.

The toll was up from 42 on Friday evening.

The authorities have not given a figure for the number of residents who could be trapped under levelled buildings, which include a hospital that collapsed with more than a dozen patients and staff inside.

At least one hotel had partially collapsed, while the regional governor's office also suffered extensive damage.

"We're running out of food. There hasn't been any aid from the government yet," 24-year-old survivor Desti told AFP from hard-hit Majene, adding that some survivors at the camp needed medical attention.

"Some people are using coconut leaves as mats," she added.

About 15,000 residents have fled to temporary shelters and nearly 190 people were being treated for serious injuries, local authorities said.

Heartfelt solidarity

The Pope said he was "saddened" to learn of the quake.

"His Holiness Pope Francis expresses his heartfelt solidarity with all those affected by this natural disaster," the Vatican said in a statement.

"He prays for the repose of the deceased, the healing of the injured and the consolation of all who grieve."

Images from the scene on Friday showed residents trying to flee Mamuju in cars and motorbikes as they drove past corrugated metal roofs and other building debris scattered on the roadside.

But landslides triggered by heavy rains and the quake blocked the main access road out of the seaside city.

The meteorological agency warned residents that the area could be hit by strong aftershocks and to avoid the beachfront in case of a tsunami.

The city's airport had also been damaged, the authorities said.

The Indonesian Red Cross said it was rushing medical and relief supplies to the scene, with its teams working to help find trapped residents.

Save the Children warned that the young were among the most at risk.

"While the extent of the earthquake damage is still unclear, we know children are often the most vulnerable following disaster," it said.

"It will be essential that children are prioritised in any response, as they may have witnessed the death of loved ones or become separated from their parents."

The quake's epicentre was 36km south of Mamuju and it had a relatively shallow depth of 18km.

Indonesia experiences frequent seismic and volcanic activity due to its position on the Pacific "Ring of Fire", where tectonic plates collide.

In 2018, a 7.5-magnitude quake and a subsequent tsunami in Palu on Sulawesi left more than 4,300 people dead or missing.

On Dec 26, 2004, a 9.1-magnitude earthquake struck off the coast of Sumatra and triggered a tsunami that killed 220,000 throughout the region, including around 170,000 in Indonesia.