An earthquake with an initial magnitude of 6.5 was recorded off the Indonesian island of Sumatra on Thursday (Jun 2), the US Geological Survey (USGS) reported.
The quake, which had an initial magnitude of 6.2, was centred about 155 kilometres south of Padang at a depth of about 40 kilometres, the USGS said. There were no immediate reports of damage or injury.
The quake took place at 5.56am local time (6.56am, Singapore time), shortly before dawn, when many people would still have been in bed.
A witness reported initial panic after the latest quake, which struck before dawn and lasted about 30 seconds. Residents rushed out of their homes and into the streets, but with no apparent signs of damage of injury, things quickly returned to normal.
There were reports of tremors in neighbouring Singapore.
Electricity cut out in some places after the quake but was restored shortly afterwards, said the journalist, and people were not ordered to evacuate their homes.
Wandono, a senior official from Indonesia's Meteorology, Climatology and Geophysics Agency, said the quake did not have the potential to cause a tsunami.
"So far we have not received any reports of damage," added the official.
A few minutes after the quake, Padang's mayor announced over the radio that it had no potential to cause a tsunami.
Phil Cummins, senior seismologist at Geoscience Australia, said the quake was not large enough to trigger a tsunami.
"People would have felt it and there may be some minor damage, but it was offshore and deep so damage would be limited," he told AFP.
There was no immediate indication of whether the quake had caused any casualties or damage. Indonesia experiences frequent seismic and volcanic activity due to its position on the Pacific "Ring of Fire," where tectonic plates collide.