The earthquake was followed by numerous aftershocks and briefly triggered a tsunami warning. Waves measuring less than one metre were reported in several coastal locations before authorities cancelled the warning approximately three hours later.
The greatest reported loss of life occurred near the port town of Maumere on Flores Island. Fathur Rahman, who leads the local rescue agency, said emergency teams had recovered 20 bodies. Six people were injured, while two others remained trapped beneath debris.
Rescue operations were proving difficult in Nagekeo, the area closest to the earthquake's epicentre. Officials said communication services had been disrupted, while landslides prevented rescuers from reaching the region by road. A second team attempted to travel there by ferry.
The national disaster management agency, BNPB, said around 2,000 people had left their homes in Nagekeo as a precaution. Several homes, warehouses and government buildings were reportedly damaged. Authorities also reported electricity failures and severe traffic congestion in parts of the area.
East Nusa Tenggara Governor Emanuel Melkiades Laka Lena said at least five people were killed when buildings collapsed while residents were sleeping. However, the BNPB initially reported a lower death toll of one person and four injuries while officials continued to verify information from affected areas.
Videos verified by Reuters showed residents running through the streets as parts of buildings collapsed in Maumere. Hospitals also took precautions, with one facility in Ende moving patients outdoors following the strong shaking.
Residents across East Nusa Tenggara, West Nusa Tenggara and parts of South Sulawesi reported intense movement that lasted close to a minute in some locations.
One resident of Talibura village, identified as 51-year-old Nona, described the frightening experience. She said 13 members of her family were inside their home when the earthquake struck and everyone rushed outside for safety.
Indonesia's geophysics agency, BMKG, recorded the main earthquake at 4:58 a.m. local time at a depth of approximately 15 kilometres. Several aftershocks followed.
The region has experienced major earthquakes before. In 1992, a magnitude-7.5 earthquake struck the same general area and caused widespread destruction.
Indonesia lies along the Pacific Ring of Fire, a region where several tectonic plates meet and where earthquakes and volcanic activity are common. Australia's tsunami warning centre said the latest earthquake did not pose a tsunami threat to Australia's mainland, islands or territories.
