A powerful earthquake struck off Indonesia's Sumatra island on Wednesday, prompting residents fearful of a tsunami to flee to higher ground.
Indonesian authorities issued a tsunami warning but lifted it more than two hours later.
The US Geological Survey (USGS) said the quake struck at a magnitude of 7.9 some 660 kilometres south-west off Sumatra, at a depth of 10 kilometres.
It hit at 7:49 pm local time (1249 GMT), the agency said.
There were no reports of damage or casualties on Sumatra and the Mentawai island chain, the area closest to the quake epicentre, said Sutopo Nugroho, spokesman for Indonesia's National Disaster Management Agency.
"According to reports from the areas where the earthquake was felt, they are all safe," said Sutopo.
Indonesia's Meteorology, Geophysics and Climatology Agency issued the tsunami warning for the Mentawai chain, 150 kilometres off the western coast of Sumatra, and parts of Sumatra.
People in Padang, the capital of West Sumatra, ran to higher ground after mosques echoed tsunami warnings, said resident Muhammad Ridho.
"People panicked and fled on motorcycles and on foot, creating traffic jams," he said.
Australia issued a tsunami warning for Christmas Island and Cocos Island.
In October 2010, a 7.7-magnitude quake triggered a tsunami off the Mentawai islands, which then had a population of 68,000 people. More than 500 people were killed, while tens of thousands were displaced.
The Mentawai chain comprises 70 islands and islets.
The world's most quake-prone regions are located around the Pacific Ocean from Japan down to the Philippines and Indonesia and in the Americas, from Alaska to Chile - named the Pacific Ring of Fire, where about 90 per cent of the world's earthquakes occur.
A powerful earthquake off Sumatra on December 26, 2004 triggered the Indian Ocean tsunami that killed 230,000 people in 15 countries.