The tremor hit at a depth of around 60 miles, the agency said. The quake appears to have struck between Indonesia’s Maluku and Timor Leste.
The AFP news agency reported that no tsunami alert was issued following the tremor.
Residents in the area said they were awoken by shaking beds and buildings, and they were forced to flee.
“People were asleep, we screamed. People ran because of the quake, beds shook,” resident Oce Karmomyana was quoted by the Daily Mail as saying.
The Richter seismic scale usually classifies a 6.8 magnitude temblor as “a strong earthquake,” according to the USGS.
“Because of the logarithmic basis of the scale, each whole-number increase in magnitude represents a tenfold increase in measured amplitude; as an estimate of energy, each whole number step in the magnitude scale corresponds to the release of about 31 times more energy than the amount associated with the preceding whole number value,” the agency’s website says.
Indonesia and other Pacific island nations are located on the Ring of Fire, which is an especially earthquake-prone region that encircles the Pacific Ocean. Other than earthquakes and tsunamis, the region also experiences a number of volcanic eruptions.
One of the worst earthquakes and tsunamis in recorded history occurred off the coast of Sumatra, Indonesia in 2004, killing at least 200,000 people, according to the USGS. In 2018, a tsunami hit the city of Palu on Indonesia’s Sulawesi, killing thousands of people.