Indonesian rescue workers have been digging through mounds of mud and rubble to search for missing people after a landslide at an illegal gold mine on Sulawesi island killed at least 23 people, with the toll expected to rise.

At least 35 people were still missing, a rescue official said on Tuesday, after the incident on the central island.

Hundreds of rescue workers were deployed, as well as a helicopter, to the area located more than 2,000km (1,200 miles) east of the capital, Jakarta.

Unlicensed mines are common across the mineral-rich Southeast Asian archipelago, where abandoned sites attract locals who hunt for leftover gold ore without proper safety equipment. A quarter of the more than 8,600 unlicensed mines are gold mines.

The landslide hit a remote village in Bone Bolango district of Gorontalo province on Sunday following intense rains that engulfed the miners and nearby residents.

Rescue agency official Ida Bagus Nyoman Ngurah Asrama told the AFP news agency that 66 people survived.

More than 270 people, including police officers and soldiers, have been deployed as part of the search and rescue operation over the last two days.

Afifuddin Ilahude, a local rescue official, said the authorities sent in rescuers with heavy equipment in an operation hampered by heavy rains, unstable soil and rugged, forested terrain.