Another powerful earthquake struck Indonesia's Sumatra island Monday, according to the U.S. Geological Survey.
The latest on Monday evening was at least the third: a 6.9-magnitude aftershock strike off the coast of Sumatra, according to UGS.
No tsunami warning was immediately issued.
It appeared to be at least the third in a series of quakes, with two or more strong ones reportedly hitting the same region earlier on Monday.
There was a brief tsunami warning after the first quakes, but no reports of damage, injuries or deaths.
The second quake had a preliminary magnitude of about 6.7. Another, which occurred early Monday morning, had a magnitude of 7.3, according to the U.S. Geological Survey.
The geophysics agency issued a tsunami bulletin following the quake first quake, but canceled it an hour later after determining no waves were generated.
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.