The epicentre of the quake, which struck at 1.28 a.m. Jakarta time, was six kilometers (3.73 miles) northeast of Majene city at a depth of 10 kilometers, according to Indonesia’s Meteorology, Climatology and Geophysics Agency.
More than 600 residents of the Majene area had been injured and 15,000 have been displaced, according to the country’s National Board for Disaster Management (BNPB).
Thousands of residents fled their homes to seek safety following the quake, which could be felt strongly for five to seven seconds and damaged at least 300 houses, BNPB said.
Other buildings have also been badly damaged, including a military command office in Majene, and the Mitra Manakara private hospital, hotels and government building in the neighboring Mamuju area.
Many people are still trapped under collapsed buildings, according to local search and rescue teams.
“Our obstacles here is that we don’t have heavy equipment to rescue them,” Saidar Rahmanjaya, Head of Local Search and Rescue Agency of Mamuju West Sulawesi, told local television.
Another difficulty was the lack of communication among rescue teams, as local telephone networks were down following the quake, he said, adding that there were eight locations where people were in urgent need of rescue.
Shalahuddin Salman, a resident of Mamuju, said many people were trapped because they were sleeping when the quake struck in the middle of the night.
“We saved four family members but one still can’t be evacuated,” he told CNN after he and a few others rescued a family from underneath a collapsed building. “(He’s) trapped inside the building. We believe he is dead.”
Shalahuddin said he worried that many people were trapped under the debris of the Mitra Manakara private hospital, an eight-floor structure that had been flattened by the quake.
Meanwhile, thousands of people who were able to flee have chosen to stay away from their homes out of fear of another earthquake or tsunami, said West Sulawesi’s Police Grand Commissioner Syamsu Ridwan.
“Some of them are going to the higher place to avoid tsunami, although we have a confirmation that we have no tsunami after this big earthquake,” he said.
The country’s Meteorology, Climatology and Geophysics Agency said the earthquake did not trigger a tsunami based on meteorology and climatology agency modeling.
The earthquake also triggered power outage and caused three landslides along the main road connecting Majene and Mamuju.
Hours earlier on Thursday, a 5.9-magnitude earthquake struck in the same district damaging several houses.
Indonesia’s disaster agency said a series of quakes in the past 24 hours had caused at least three landslides, and the electricity supply had been cut.
Straddling the so-called Pacific ‘Ring of Fire’, Indonesia, a nation of high tectonic activity, 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 of people.