The Indonesian and Australian authorities have issued early tsunami warnings after a shallow 7.9 magnitude earthquake struck off the southwest coast of Sumatra island in the Indian Ocean.
The US Geological Survey, which initially reported the tremor at 8.2 magnitude, said the massive earthquake hit at 12.49pm GMT at a depth of just 10km (six miles).
The size and depth of the quake has led national authorities to issue tsunami warnings, though the Australian authorities stressed that sea level observations have not yet confirmed whether a tsunami has been generated.
Specific warnings were issued for Western Australia including Perth, Christmas and Cocos Island, while Indonesia put out alerts for West Sumatra, North Sumatra and Aceh, the National Meteorological Agency said.
Reports from the ground in Indonesia suggest damage from the earthquake itself will be limited. Local media outlets described people rushing out of their homes upon feeling the quake, whose epicentre was around 600km (370miles) off the coast of Sumatra.
The area, and the province of Aceh in particular, was badly hit by an Indian Ocean tsunami most recently in 2004.