The quake was at a depth of 10 km (6.21 miles), the US Geological Survey (USGS) said.
Indonesia's meteorology, climatology and geophysical agency said the quake was felt in cities in the area including Bengkulu, which was the nearest to the epicentre, and Padang. "Up to now, there have been no reports of damage yet following the earthquake," the agency said in a statement "Our modelling showed no tsunami potential from this quake," it said.
Twitter user @pjv_dreamer said in a post there had been an initial quake and then a larger more powerful tremor that felt like "riding a swing" in an amusement park, shaking your body from side to side.
Indonesia sits on the Pacific's seismically active "Ring of Fire" and has suffered deadly earthquakes and tsunamis in the past. The most devastating in recent Indonesian history was on Dec. 26 in 2004, when a magnitude 9.5 quake off Sumatra triggered a massive tsunami that killed around 226,000 people along the shorelines of the Indian Ocean, including more than 126,000 in Indonesia. In September 2018, Palu, on the Indonesian island of Sulawesi, was devastated by a 7.5-magnitude earthquake and a powerful tsunami it unleashed, killing more than 4,000 people.