Heavy rain on Wednesday halted the search for 30 people believed to be trapped under a landslide that engulfed an unauthorised gold mine on Indonesia’s Sulawesi island over the weekend, killing at least 23 people.

More than 100 people were digging for grains of gold in the remote village of Bone Bolango in Gorontalo province on Sunday when tons of mud plunged down the surrounding hills and buried their makeshift camps.

The search was suspended on Wednesday afternoon because of heavy rain, said Heriyanto, head of the provincial search and rescue office. Rescuers have not yet been able to locate the missing people, he added.

Rescuers search for victims at the site of a landslide in Suwawa on Sulawesi Island, Indonesia (BASARNAS/AP)

The National Search and Rescue Agency said on Wednesday that 92 villagers managed to escape from the landslide. Several of them were pulled out by rescuers, including 18 with injuries.

It added that 23 bodies have been recovered, including that of a four-year-old boy, while 30 people are still missing.

More than 1,000 personnel, including army troops, have now been deployed in the search, said Edy Prakoso, the agency’s operations director.

He said the Indonesian air force would send a helicopter to speed up the rescue operation, which has been hampered by heavy rain, unstable soil and rugged terrain.

An Indonesian National Search and Rescue Agency worker tends to an injured victim of the landslide in Suwawa on Sulawesi island (BASARNAS/AP)

Photos released by the agency showed an excavator removing tons of mud and rocks that were blocking access to the site.

Informal mining operations are common in Indonesia, providing a tenuous livelihood for thousands labouring in conditions that pose a high risk of serious injury or death.

Landslides, flooding and collapses of tunnels are just some of the hazards facing miners. Much of gold ore processing involves highly toxic mercury and cyanide, with workers frequently using little or no protection.

The country’s last major mining-related accident was in April 2022, when a landslide crashed on to an illegal gold mine in North Sumatra’s Mandailing Natal district, killing 12 women who were looking for gold.

Environmental activists have campaigned for years to shut down such operations across the country, especially on Sulawesi, where the practice has grown. Sunday’s landslide reignited their calls.

“The local government which has allowed illegal gold mining activities in this area to continue has contributed to the deadly disaster,” said Muhammad Jamil, who heads the legal division of the Mining Advocacy Network, an environment watchdog.

He said many people share the blame for illegal gold mining, from those working on the ground up to officials in the local council and the police.

“This mafia network appears to have helped shield the miners from law enforcement, even as they tear up protected forests,” said Mr Jamil. “When natural resources such as rivers, forests, land and the sea are damaged, it will be a complete loss to the country’s economy.”

Ferdy Hasiman, a mining and energy researcher at Alpha Research and Datacentre, said the proliferation of pit mines has long been blamed for environmental damage in upstream areas that has in turn exacerbated flooding and landslides downstream.

“Flash floods and landslides would persist if illegal mining and the deforestation in the practice continue,” he said. “We call on the local and central government to expand their efforts to shut down illegal gold mining across the country.”