Heavy rain and landslides hit the city of Sorong in West Papua Province for approximately four hours on Thursday afternoon (July 17).
Thousands of residents' houses and several main roads were submerged in knee-deep floodwater.
An Indonesian Navy's National Army hospital was also flooded, and a number of patients were forced to evacuate.
The National Search and Rescue Agency have been deployed three teams to the most severely affected locations.
Afrisal, the Head of this National SAR Agency search, said they are prioritising women and children currently trapped inside their homes.
According to the Sorong Disaster Mitigation Office (BPBD), currently, there are four dead, and three reported injured.
Three of the deaths were caused by a landslide and one death was caused by electrocution.
Rescue operations are ongoing.