The epicentre was north of the island of Flores in Indonesia’s East Nusa Tenggara province, where the quake sparked terror after hitting at around 3.20am.
Indonesia’s Meteorology, Climatology, and Geophysical Agency known as BMKG earlier reported the earthquake as a magnitude 7.4, and warned of “potential tsunami”.
“I was in the field. People ran in panic. I am still… scared,” said Nuraini, a resident of Adonara island in the East Flores regency, told AFP news agency.
No significant damage or deaths were immediately reported from the areas where the quake was felt, but authorities urged caution.
The USGS said the chance of casualties was low, while noting that “recent earthquakes in this area have caused secondary hazards such as tsunamis and landslides that might have contributed to losses”.
“Everyone ran out into the street,” Agustinus Florianus, a resident of Maumere town on Flores island, told Reuters news agency.
Tsunami warnings were issued for the areas of Maluku, East Nusa Tenggara, West Nusa Tenggara and Southeast and South Sulawesi, after the quake hit 112 km (69.59 miles) northwest of Larantuka, in the eastern part of Flores, at a depth of 12 km.
A 5.6-magnitude aftershock hit Larantuka after the first quake, according to reports.
Alfons Hada Betan, head of East Flores Disaster Mitigation agency in Larantuka also said there were no immediate reports of damage and the quake was felt for several minutes as people fled from their homes.
People said on social media the earthquake was also felt strongly in Makassar, South Sulawesi.
Indonesia experiences frequent quakes and volcanic eruptions due to its position on the Pacific “Ring of Fire”, an arc of intense seismic activity where tectonic plates collide that stretches from Japan through Southeast Asia and across the Pacific basin.