Western Indonesia has been hit by a 7.8 magnitude earthquake, the US Geological Survey (USGS) reports.
There have been no immediate reports of damage.
According to the USGS, the earthquake struck at 19:49 local time. It said the epicenter was 500 miles south-west of the city of Padang, and 15 miles deep.
Indonesian officials issued a tsunami warning for the regions of West Sumatra, North Sumatra and Aceh.
Australia also issued a tsunami warning for Cocos Island and Christmas Island in the Pacific. It also issued a tsunami watch for Western Australia but this was later lifted.
Australia’s Bureau of Meteorology said evacuations were not required on the islands but advised people to “get out of the water and move away from the immediate water’s edge”, because of the risk of dangerous waves and currents.
Authorities in India said their initial assessment was that there was no tsunami threat. Sri Lankan media also reported the country’s disaster management centre as saying there was no threat.
The earthquake was felt strongly in Padang for a few seconds, AFP reports, with people running out of their homes to higher ground.
Traffic ground to a halt and there was a sense of panic on the streets.
In 2004, an 8.9 magnitude earthquake triggered the world’s deadliest ever tsunami, killing more than 200,000 people.