A strong earthquake measuring 7.7 on the Richter scale struck off the eastern coast of Indonesia in the early hours of August 15, 2026. The quake, which occurred at 4:58 AM local time, was recorded at a depth of about 15 km. Following the main shock, the region experienced several aftershocks, the largest of which was measured at 6.1.

The Indonesian Meteorology, Climatology, and Geophysics Agency (BMKG) reported that small tsunamis, with heights ranging from 19 to 30 cm, were recorded in some areas, prompting residents to evacuate to higher ground. However, the Australian Tsunami Warning Center indicated that the underwater earthquake did not pose a tsunami threat to the Australian mainland or its islands.

Reports from the affected areas, including Ruteng, indicated that some buildings sustained damage. Video footage from a port in Maumere, the main city in Sikka Regency on Flores Island, showed parts of a building collapsing amidst dust and debris as people fled the area in panic.

In Ende district, East Nusa Tenggara province, a hospital evacuated patients due to the strong tremors. Lukas Lotar, a 31-year-old hospital staff member, described the intensity of the shaking, stating, "Suddenly everything started to shake, and I was terrified. Patients also ran out of the hospital." Hundreds of residents in Maumere and Nagekeo were reported to have moved to higher ground.

Some locals noted that the sea level receded after the earthquake, raising concerns about the potential for a tsunami. Indonesia is frequently affected by earthquakes and volcanic activity due to its location on the Pacific Ring of Fire. Notably, a devastating 9.1 magnitude earthquake off the coast of Sumatra in 2004 resulted in approximately 220,000 fatalities across the region, with around 170,000 in Indonesia alone. In 2018, an earthquake on Lombok claimed over 550 lives, and a 7.5 magnitude quake and tsunami in Palu on Sulawesi Island at the end of that year resulted in more than 4,300 deaths or disappearances.