More rain has brought further misery to survivors of landslides and floods that have killed at least 65 people on Indonesia's Sulawesi island, rescue officials said on Wednesday.

Days of heavy downpour have caused landslides and floods up to three metres (10 ft) high, submerging hundreds of homes in Central Sulawesi province, which lies about 1,700 km (1,056 miles) northeast of the capital, officials said.

In neighbouring South Sulawesi province, a landslide triggered by heavy rains killed eight people on Tuesday night, the National Disaster Relief Coordination Agency said.

The latest deaths brought the number of people killed in landslides and flooding to 65, with a further 25 missing, according to the agency.

The poor weather and a lack of heavy equipment in Central Sulawesi were hampering efforts to rescue about 23 people believed buried under the landslides and to provide food for survivors, said Frets Abast, coordinator of provincial disaster relief teams.

Helicopter food drops were halted on Wednesday because of the rain, he said.

"The rescue work is still being done using manual equipment. There's no heavy equipment at all," Abast told Reuters.

He said vehicles carrying relief supplies had difficulty reaching the disaster zone because roads and bridges had been submerged or destroyed.

Deadly landslides occur frequently in Indonesia, where tropical downpours can quickly soak hillsides stripped of trees with little vegetation to hold the soil.

Central Sulawesi is also one of Indonesia's key cocoa growing areas. The Southeast Asian country is the world's third largest producer of cocoa beans.

Herman Agan, chairman of the Indonesia Cocoa Association for Central Sulawesi, said the province's cocoa output may be about 10 percent lower than earlier expectations of around 160,000 tonnes because of the floods and landslides.