A strong earthquake has struck near the Indonesian island of Sumatra, say seismologists.
The epicentre of the quake, which had an estimated magnitude of 6.7, was about 120km (75 miles) south-west of the city of Padang, officials said.
There were no immediate reports of damage, but some people fled the coast.
The latest tremor revived fears of a repeat of the 26 December tsunami disaster, which killed an estimated 300,000 people in a dozen countries.
Two-thirds of the deaths occurred in Indonesia.
However, no tsunami warning was issued on Sunday.
The latest tremor struck at struck at 1729 local time (1029 GMT) and was felt as far away as Singapore.
Many people were reported to have fled their homes in Padang, after a radio broadcast by city mayor Fauzi Bahar.
"Many people in Padang are panicking," said Yusuf, an official from Indonesia's Geophysics and Meteorology Agency (IGMA).
"People have left their houses, specially those living on the coast," he said, according to the Associated Press news agency.
The Pacific Tsunami Warning Center in Honolulu, in the US state of Hawaii, said: "Earthquakes of this size sometimes generate local tsunamis that can be destructive along coasts located within a few hundred kilometres of the earthquake epicentre."
It urged local authorities to "be aware of this possibility and take appropriate action".
Scientists have warned that the Indian Ocean faultline could deliver another major earthquake, and tremors have been felt repeatedly in the area since the 9.3-magnitude jolt that unleashed the 26 December tsunami.
Two weeks ago, an aftershock from that earthquake killed more than 600 people on the Indonesian island of Nias.
On that occasion, rapid response plans put in place after December's disaster were activated promptly.
An integrated tsunami warning system for the region will not be ready until the end of next year, but most countries have a contingency plan.