Flash floods on eastern Indonesia's Sulawesi island killed three people and damaged scores of buildings, officials said Saturday.

"One adult and two children were killed (Friday) in the district of Donggala in Central Sulawesi. Many homes have been damaged, so people are staying with their relatives or sleeping in local schools," National Disaster Mitigation Agency spokesman Sutopo Purwo Nugroho told AFP.

Three hours of torrential rain caused a river to overflow into three villages, seriously damaging more than 70 homes and two bridges, Nugroho said.

"There is heavy flooding in this part of the world at the moment, with Thailand and the Philippines more seriously affected," Nugroho said.

"There is likely to be more bad weather to come."

Local agencies have set up a health post for victims and are collecting data on people affected.

Indonesia has been repeatedly afflicted by deadly floods and landslides in recent years, with activists warning that logging and a failure to reforest denuded land in the world's fourth-most populous country are often to blame.

Floods in Indonesia's Papua region killed more than 140 people and displaced around 5,000 last year in October, when the tropical wet season hit.

Deadly floods have also killed about 300 people in Thailand and around 100 in the Philippines.