Earthquake strikes near Sumatra
(CNN) -- An earthquake has struck near Indonesia's northern island of Sumatra, triggering fears of new tsunamis, but none were reported.
The U.S. Geological Survey said the quake, just before 5:30p.m. local time (1030 GMT) had a magnitude of 6.8. The National Oceanic and Atmospheric Administration said it was a 6.7.
It was centered 115 kilometers (70 miles) southwest of Padang, Sumatra, the USGS said.
Over the next couple of hours, a series of quakes followed. A spokesman for Indonesia's meteorological agency said the additional quakes were aftershocks, and all had magnitudes lower than the first.
The spokesman, named Wijayanto, said the quakes caused panic, but there were no reports of deaths or injuries. Tsunamis would have happened not long after the quake, and none were seen, he said.
The NOAA did not issue any tsunami warnings or watches.
In a bulletin after the first quake, the NOAA said, "Earthquakes of this size sometimes generate local tsunamis that can be destructive along coasts located within a few hundred kilometers of the earthquake epicenter" -- a distance that could include coasts of Sumatra.
When no tsunamis materialized Sunday evening, Indonesian authorities urged people who had fled their homes to return.
On March 28, Indonesia's northern Sumatra island was affected by a major earthquake -- which the USGS measured at 8.7 magnitude -- that killed at least 600 people. Authorities feared possible tsunamis, but there were none. Two days later, on March 30, a 6.3-magnitude aftershock struck.
The massive tsunami disaster on December 26 that left widespread destruction throughout the region was set off by a quake that the USGS measured at 9.0. About 300,000 people were killed or remain missing.