The U.S. Geological Survey said the epicenter of the quake, registering 7.5 on the Richter scale, was about 195 miles south-southeast of Banda Aceh on Sumatra, CNN reported. The first quake began about 3 p.m. An hour later, a 5.2-magnitude earthquake shook the same area.

The three victims -- two women and a man -- were in their late 60s to early 70s, local officials told CNN. A Health Ministry official said the earthquake damaged several structures.

Indonesian disaster officials said Simeulue regency was virtually unreachable, adding that an assessment team would be dispatched Thursday.

The Pacific Tsunami Warning Center issued a bulletin saying parts of the Sumatran coast nearest the epicenter were at risk of a tsunami, CNN said.

A 2004 earthquake near Banda Aceh killed hundreds of thousands of people, CNN said. The 2004 quake caused a tsunami affecting the entire Indian Ocean, leaving more than 300,000 dead or still listed as missing, information compiled by the United Nations indicated.