A tremor measuring 4.7 on the Richter Scale hit Padang, capital of West Sumatra province, on Wednesday but there was no immediate report of casualty.
The epicenter of the tremor was traced at 1.52 degrees southern latitude and 101.01 degrees eastern longitude at a depth of 33 kilometers below the sea level, official news agency Antara reported.
The location of the epicenter was about 98 kilometers west of Padang, which was around Mentawai Islands, Eva, an officer of the Jakarta Meteorology and Geophysics (BMG) said.
Eva said earlier on Wednesday morning that North Sumatra was also jolted by an earthquake measuring 5 on the Richter Scale, but the inhabitants could not felt it because its modified marcelli intensity (MMI) was very low.
The epicenter of Wednesday's earlier quake was located at 7.64 degrees southern latitude and 73.69 western longitude at a depth of 33 km below the sea level, around 46 km off Gunung Sitoli island.