One person died and 29 others were injured after a magnitude 5.8 undersea earthquake struck near Poso in Indonesia’s Central Sulawesi province on August 17, 2025. Two of the injured were reported to be in critical condition.
The US Geological Survey placed the earthquake about 15 kilometres north of Poso district. It occurred on Sunday morning and was followed by at least 15 aftershocks. Indonesian authorities did not issue a tsunami warning.
Most of the injured were members of a congregation attending a morning service at a church, according to Abdul Muhari, spokesperson for Indonesia’s National Disaster Mitigation Agency. Video circulating after the quake showed damage to the church, and local disaster officials began rapid field assessments to determine the wider impact. Most injured people were taken to the regional government hospital.
A separate local report identified the person who died as Katrin Kande and said Masani village officials announced the death through a public-address system after it was confirmed at Poso Regional Hospital. The reporting did not provide further details about the circumstances of the death.
The earthquake added to a long record of seismic disasters across Indonesia, an archipelago of more than 270 million people. The country sits on the Pacific “Ring of Fire,” a broad zone of active faults and volcanoes where earthquakes, eruptions and tsunamis occur frequently.
Recent events have demonstrated the range of risks. In 2022, a magnitude 5.6 earthquake in Cianjur, West Java, killed at least 602 people. That was Indonesia’s deadliest earthquake since the 2018 earthquake and tsunami in Sulawesi, which killed more than 4,300. In 2004, a much larger earthquake in the Indian Ocean generated a tsunami that killed more than 230,000 people across a dozen countries, with most deaths in Indonesia’s Aceh province.
The August 17 tremor was far less destructive than those disasters, and the absence of a tsunami warning limited the immediate coastal threat. Its effects were nevertheless concentrated in an occupied place of worship, producing dozens of casualties from a moderate-magnitude event.
Officials continued checking buildings and communities around Poso as aftershocks followed the main quake. The field assessments were important because initial reports focused primarily on the damaged church and hospital admissions. With two patients critically injured and aftershocks continuing, authorities faced both an immediate medical response and the need to establish whether further structural damage had occurred elsewhere in the district.
