An aftershock jolted Indonesia's Sulawesi island yesterday as rescue workers combed the rubble of collapsed buildings for survivors after an earthquake killed at least 46 people on Friday and sent thousands of residents fleeing in panic.

The country's disaster mitigation agency said no damage or casualties were reported from yesterday's magnitude-5.0 tremor in the West Sulawesi districts of Mamuju and Majene, which shook the area a day after the magnitude-6.2 quake.

Agency head Doni Monardo told local TV the search continued for people who could still be trapped alive under rubble, and a spokesman told reporters emergency measures had been put in place in the province to help rescue efforts.

More than 820 people were injured and about 15,000 left their homes after the quake, the agency said. Some sought refuge in the mountains, while others went to cramped evacuation centres, witnesses said.

Friday's quake and its aftershocks damaged more than 400 homes and two hotels, as well as flattening a hospital and the office of a regional governor, where authorities told Reuters several people were still trapped.

Nur Samsiah said her son, a nurse, had been killed as he worked at the collapsed hospital.

"My son was on the ground floor of the building and he couldn't run for cover," she said.

Arianto Ardi from the search and rescue agency in Mamuju told Reuters that search efforts would focus on the two hotels.

Dwikorita Karnawati, the head of the national meteorology agency, told local television yesterday another quake was possible and could reach a magnitude of 7.0, urging residents to keep out of the sea because of the tsunami risk.

Straddling the so-called Pacific Ring of Fire, Indonesia is regularly hit by earthquakes.

In 2018, a devastating 6.2-magnitude quake and subsequent tsunami struck the city of Palu, in Sulawesi, killing thousands.