A strong earthquake rocked parts of Indonesia's Sumatra Island on Wednesday, US Geological Survey said on its web site.
There are no immediate reports of any casualties or damage.
The 6.1-magnitude hit 115 miles northwest of Bengkulu and was felt in cities along Sumatra's west coast.
The temblor was not strong enough to cause a tsunami. It was followed by another 5.1-magnitude aftershock.
The quake came a week after 8.4-strong tremblor killed 23 people along the western coast of Sumatra. More than 60 strong aftershocks have followed the massive earthquake - including a magnitude 7.8 and a 7.1.
Indonesia, which sits on the Pacific Basin's "Ring of Fire" - an arc of volcanos and fault lines, is prone to seismic upheaval.
In December 2004, a massive earthquake off Sumatra island triggered a tsunami that killed more than 230,000 people, including 160,000 people in Indonesia's province of Aceh.