An earthquake with a preliminary magnitude of 6.6 rattled Indonesia's Sumatra island, the US Geological Survey said, sending frightened residents running from their homes.
The quake struck yesterday night just off the coast of Bengkulu province, about 600 kilometres west of the capital, Jakarta, the USGS said. It had a depth of around 35 kilometres.
There were no immediate reports of damage or injuries, said Gian Ginanjar, an official at the Indonesian Meteorological and Geophysics Agency.
The jolt, in the same area shaken by an 8.4 quake in September that killed 25 people, did not trigger a tsunami, national authorities said.
Many people, however, fled their homes fearing they would collapse, witnesses said.
"It shook everything in my house for a minute," Irwan Nurjanah said by telephone from Bengkulu. "I couldn't do anything but run with the others. I don't want to be buried in my house."
Just to the north in the city of Padang, which was closer to the epicenter, some people ran inland or to higher ground in a panic, fearing giant waves would come, an AP reporter on the scene said.
Patients were temporarily evacuated from a hospital in Padang.
Indonesia, which straddles a series of active fault lines, is prone to seismic and volcanic activity. A giant earthquake along the same coast spawned the large tsunami that killed more than 230,000 people in a number of countries in December 2004.