A fresh earthquake struck off western Sumatra on Tuesday in the wake of strong tremors the day before, triggering another tsunami alert, Indonesia's meteorology agency said.
The agency said the quake measured 7.0 on the Richter scale and had an epicentre about 171 km (106 miles) southwest of Painan, West Sumatra, at a depth of 27 km.
Suharjono, head of the agency's quake division, said many areas had felt Tuesday's quake but there was no information so far on any possible damage. The tsunami alert - like those of the day before - was quickly lifted.
A huge earthquake measuring more than 9 struck off Sumatra on Dec. 26, 2004, causing a devastating tsunami and more than 230,000 deaths in countries across the region.
The U.S. Geological Survey said that on Monday one quake, felt in neighbouring Singapore, had a magnitude of 7.3 and was at a depth of 35 km (22 miles).
That also prompted a tsunami warning but the meteorology agency lifted the alert after 45 minutes. Two other strong aftershocks hit the same area hours later.
The same area was hit by a more powerful quake of magnitude 8.4 in September last year that killed at least 25 people and toppled thousands of homes.
Indonesia suffers from frequent earthquakes as it lies in the so-called "Pacific Ring of Fire," an area of intense seismic activity where a number of tectonic plates collide.
