A strong earthquake shook Indonesia's Sulawesi island just after midnight, causing landslides and sending people fleeing from their homes in the nighttime darkness.

Rescuers search for survivors among the ruin of a building damaged by an earthquake in Mamuju, West Sulawesi, Indonesia, Friday, Jan. 15, 2021.
Rescuers search for survivors among the ruin of a building damaged by an earthquake in Mamuju, West Sulawesi, Indonesia, Friday, Jan. 15, 2021. (AP)

A strong, shallow earthquake shook Indonesia's Sulawesi island, causing landslides, levelling a hospital, severely damaging other buildings and sending people fleeing from their homes in the nighttime darkness.

At least 42 people were confirmed dead but authorities were still collecting information from devastated areas.

More than 600 people were injured during the magnitude 6.2 quake, which sent people fleeing their homes in the darkness, triggering panic among the terrified residents of the island, which was hit by a huge quake and tsunami two and a half years ago that killed thousands.

So far, 29 bodies have been hauled from beneath crumpled buildings in Mamuju, a city of about 110,000 in West Sul awesi province, while another eight were killed south of the area after the quake struck.

"We don't know how many more are missing," said Arianto from the rescue agency in Mamuju, who like many Indonesians goes by one name.

"There are still people trapped beneath the rubble."

Separately, the national disaster agency said at least eight people had died in an area south of Mamuju, a city of some 110,000 in West Sulawesi province, bringing the total death toll to 34.

The epicentre of the earthquake was 36 kilometres (22 miles) south of West Sulawesi province’s Mamuju district, at a depth of 18 kilometres (11 miles), the US Geological Survey said.

Strong aftershocks could follow the earthquake, the chief of Indonesia's Meteorology and Geophysics agency (BMKG) said. 

Dwikorita Karnawati told a news conference there had been at least 26 aftershocks after two strong quakes had rocked the area since Thursday afternoon.

Several buildings in Majene were severely damaged, including 62 homes, a health unit centre and a military office.

The strong quake also caused power and phone service outages and landslides along roads.

Rescuers search for survivors at a collapsed building in Mamuju city on January 15, 2021, after a 6.2-magnitude earthquake rocked Indonesia's Sulawesi island.
Rescuers search for survivors at a collapsed building in Mamuju city on January 15, 2021, after a 6.2-magnitude earthquake rocked Indonesia's Sulawesi island. (AFP)

A hospital in Mamuju, a city of some 110,000 in West Sulawesi province, was levelled.

"The hospital is flat tened, it collapsed," said Arianto from the rescue agency in Mamuju city, who goes by one name.

"There are patients and hospital employees trapped under the rubble and we're now trying to reach them," he added, without giving a specific figure.

Death toll could rise

Rescuers were also trying to reach a family of eight trapped under the rubble of their destroyed home, he added.

The country's search-and-rescue agency earlier said at least one hotel had collapsed after the quake struck at 2:18 am local time Friday (1818 GMT Thursday).

It later clarified that the hotel had partially caved in, while the regional governor's office also suffered extensive damage.

A Mamuju resident said damage across the city was severe, but the full extent of the disaster and casualties was not immediately clear.

"Roads are cracked and many buildings collapsed," said 28-year-old Hendra, who also goes by one name.

"The quake was very strong... I woke up and ran away with my wife."

National Disaster Mitigation Agency spokesman Raditya Jati said three people had been killed and 24 injured.

The death toll could rise.

In a video released by the National Disaster Mitigation Agency, a girl trapped in the wreckage of a house cried out for help and said her mother was alive but unable to move out. "Please help me, it's hurt," the girl told rescuers, who replied that they desperately wanted to help her.

In the video, the rescuers said an excavator was needed to save them. Other images in the video showed a severed bridge and damaged and even flattened houses. TV stations reported the earthquake damaged part of a hospital and patients were moved to an emergency tent outside.

A damaged car and buildings are seen following an earthquake in Mamuju, West Sulawesi province, Indonesia, January 15, 2021.
A damaged car and buildings are seen following an earthquake in Mamuju, West Sulawesi province, Indonesia, January 15, 2021. (Reuters)

Another video showed a father cried hopeless, asking help from people to save his children buried under tons of his house rubble. "My children there... they are trapped inside, please help," he cried in panic. 

At least 62 houses, a public health centre and a military office were damaged in Mamuju and landslides were set off in three locations and blocked a main road connecting Mamuju to the Majene district, said Raditya Jati, the disaster agency's spokesperson.

Hours earlier, a 5.9 magnitude earthquake struck in the same district on Thursday damaging several houses.

Straddling the so-called Pacific 'ring of fire', Indonesia, a nation of high tectonic activity, is regularly hit by earthquakes.

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 December 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.

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Source: TRTWorld and agencies