A major earthquake has struck off the coast of Indonesia's Sumatra island, but there are no immediate reports of damage or casualties.
The U.S. Geological Survey said the earthquake had a magnitude of 7.5 and a depth of about 15 kilometers. Its epicenter was 78 kilometers west of Indonesia's Pagai Selantan island, off Sumatra's western coast. The quake happened Monday at 1442 UTC.
Indonesian authorities initially issued a tsunami alert but later lifted it.
Indonesia straddles several fault lines that make the vast island nation vulnerable to volcanic and seismic activity.
A giant quake hit off Sumatra's coast on December 26, 2004, triggering an Indian Ocean tsunami that killed 230,000 people, half of them in Indonesia's Aceh province.
Some information for this report was provided by AP, AFP and Reuters.